FEATURES
C-LoadTM Op Amp Drives All Capacitive Loads
Unity-Gain Stable
Maximum Input Offset Voltage: 600V
Maximum Input Bias Current: 50nA
Maximum Input Offset Current: 15nA
Minimum DC Gain, RL = 2k: 30V/mV
Input Noise Voltage: 14nV/Hz
Settling Time to 0.1%, 10V Step: 700ns
Settling Time to 0.01%, 10V Step: 1.25s
Minimum Output Swing into 1k: 13V
Minimum Output Swing into 500: 3.4V
Specified at 2.5V, 5V and 15V
Available in SO-8 Package
LT1353 in Narrow Surface Mount Package
APPLICATIO S
Battery-Powered Systems
Wideband Amplifiers
Buffers
Active Filters
Data Acquisition Systems
Photodiode Amplifiers
LT1352/LT1353
Dual and Quad 250A, 3MHz, 200V/s
Operational Amplifiers
U
DESCRIPTIO
The LT®1352/LT1353 are dual and quad, very low power, high speed operational amplifiers with outstanding AC and DC performance. The amplifiers feature much lower supply current and higher slew rate than devices with comparable bandwidth. The circuit combines the slewing performance of a current feedback amplifier in a true operational amplifier with matched high impedance inputs. The high slew rate ensures that the large-signal bandwidth is not degraded. Each output is capable of driving a 1kloadto 13Vwith15Vsuppliesanda 500 load to 3.4V on 5V supplies.
The LT1352/LT1353 are members of a family of fast, high performance amplifiers using this unique topology and employing Linear Technology Corporation’s advanced complementary bipolar processing. For higher bandwidth devices with higher supply current see the LT1354 through LT1365 data sheets. Bandwidths of 12MHz, 25MHz, 50MHz and 70MHz are available with 1mA, 2mA, 4mA and 6mA of supply current per amplifier. Singles, duals and quads of each amplifier are available. The LT1352 is available in an 8-lead SO package. The LT1353 is offered in a 14-lead narrow surface mount package.
, LTC and LT are registered trademarks of Linear Technology Corporation.
C-Load is a trademark of Linear Technology Corporation.
U
TYPICAL APPLICATIO
R1
50k
R2
5k
–
1/2
R5 1.1k
R3
5k
R4
50k
–
LT1352
– +
1/2
LT1352
VOUT
VIN +
+
GAIN = [R4/R3][1 + (1/2)(R2/R1 + R3/R4) + (R2 + R3)/R5] = 102 TRIM R5 FOR GAIN
TRIM R1 FOR COMMON MODE REJECTION BW = 30kHz
1352/53 TA01
AV = –1 1352/53 TA02
Total Supply Voltage (V+ to V–) .............................. 36V
Differential Input Voltage (Transient Only, Note 2) 10V Input Voltage .......................................................... VS
Output Short-Circuit Duration (Note 3) ........... Indefinite
Operating Temperature Range ................ – 40C to 85C
Specified Temperature Range (Note 7) .. – 40C to 85C Maximum Junction Temperature (See Below)
Plastic Package ............................................... 150C
Storage Temperature Range ................. – 65C to 150C
Lead Temperature (Soldering, 10 sec).................. 300C
TOP VIEW OUT A 1 8 V+ –IN A 2 7 OUT B A +IN A 3 6 –IN B B V– 4 5 +IN B N8 PACKAGE 8-LEAD PDIP S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 150C, JA = 130C/ W (N8) TJMAX = 150C, JA = 190C/ W (S8) | ORDER PART NUMBER | TOP VIEW OUT A 1 14 OUT D –IN A 2 13 –IN D A D +IN A 3 12 +IN D V+ 4 11 V– +IN B 5 B C 10 +IN C –IN B 6 9 –IN C OUT B 7 8 OUT C S PACKAGE 14-LEAD PLASTIC SO TJMAX = 150C, JA = 150C/ W | ORDER PART NUMBER |
LT1352CN8 LT1352CS8 LT1352IN8 LT1352IS8 | LT1353CS | ||
S8 PART MARKING | |||
1352 1352I |
Consult LTC Marketing for parts specified with wider operating temperature ranges.
SYMBOL | PARAMETER | CONDITIONS | VSUPPLY | MIN | TYP | MAX | UNITS |
VOS | Input Offset Voltage | 15V 5V | 0.2 0.2 | 0.6 0.6 | mV mV | ||
2.5V | 0.3 | 0.8 | mV | ||||
IOS | Input Offset Current | 2.5V to 15V | 5 | 15 | nA | ||
IB | Input Bias Current | 2.5V to 15V | 20 | 50 | nA | ||
en | Input Noise Voltage | f = 10kHz | 2.5V to 15V | 14 | nV/Hz | ||
in | Input Noise Current | f = 10kHz | 2.5V to 15V | 0.5 | pA/Hz | ||
RIN | Input Resistance | VCM = 12V Differential | 15V 15V | 300 | 600 20 | M M | |
CIN | Input Capacitance | 15V | 3 | pF | |||
Positive Input Voltage Range | 15V | 12.0 | 13.5 | V | |||
5V | 2.5 | 3.5 | V | ||||
2.5V | 0.5 | 1.0 | V | ||||
Negative Input Voltage Range | 15V | – 13.5 | – 12.0 | V | |||
5V | – 3.5 | – 2.5 | V | ||||
2.5V | – 1.0 | – 0.5 | V | ||||
CMRR | Common Mode Rejection Ratio | VCM = 12V VCM = 2.5V VCM = 0.5V | 15V 5V 2.5V | 80 78 68 | 94 86 77 | dB dB dB | |
PSRR | Power Supply Rejection Ratio | VS = 2.5V to 15V | 90 | 106 | dB |
SYMBOL | PARAMETER | CONDITIONS | VSUPPLY | MIN | TYP | MAX | UNITS |
AVOL | Large-Signal Voltage Gain | VOUT = 12V, RL = 5k VOUT = 10V, RL = 2k VOUT = 10V, RL = 1k VOUT = 2.5V, RL = 5k VOUT = 2 .5V, RL = 2k VOUT = 2.5V, RL = 1k VOUT = 1V, RL = 5k | 15V 15V 15V 5V 5V 5V 2.5V | 40 30 20 30 25 15 20 | 80 60 40 60 50 30 40 | V/mV V/mV V/mV V/mV V/mV V/mV V/mV | |
VOUT | Output Swing | RL = 5k, VIN = 10mV RL = 2k, VIN = 10mV RL = 1k, VIN = 10mV RL = 1k, VIN = 10mV RL= 500, VIN = 10mV RL = 5k, VIN = 10mV | 15V 15V 15V 5V 5V 2.5V | 13.5 13.4 13.0 3.5 3.4 1.3 | 14.0 13.8 13.4 4.0 3.8 1.7 | V V V V V V | |
IOUT | Output Current | VOUT = 13V VOUT = 3.4V | 15V 5V | 13.0 6.8 | 13.4 7.6 | mA mA | |
ISC | Short-Circuit Current | VOUT = 0V, VIN = 3V | 15V | 30 | 45 | mA | |
SR | Slew Rate | AV = – 1, RL = 5k (Note 4) | 15V 5V | 120 30 | 200 50 | V/s V/s | |
Full-Power Bandwidth | 10V Peak (Note 5) 3V Peak (Note 5) | 15V 5V | 3.2 2.6 | MHz MHz | |||
GBW | Gain Bandwidth | f = 200kHz, RL = 10k | 15V 5V 2.5V | 2.0 1.8 | 3.0 2.7 2.5 | MHz MHz MHz | |
tr, tf | Rise Time, Fall Time | AV = 1, 10% to 90%, 0.1V | 15V 5V | 46 53 | ns ns | ||
Overshoot | AV = 1, 0.1V | 15V 5V | 13 16 | % % | |||
Propagation Delay | 50% VIN to 50% VOUT, 0.1V | 15V 5V | 41 52 | ns ns | |||
ts | Settling Time | 10V Step, 0.1%, AV = – 1 10V Step, 0.01%, AV = – 1 5V Step, 0.1%, AV = – 1 5V Step, 0.01%, AV = – 1 | 15V 15V 5V 5V | 700 1250 950 1400 | ns ns ns ns | ||
RO | Output Resistance | AV = 1, f = 20kHz | 15V | 1.5 | | ||
Channel Separation | VOUT = 10V, RL = 2k | 15V | 101 | 120 | dB | ||
IS | Supply Current | Each Amplifier Each Amplifier | 15V 5V | 250 230 | 320 300 | A A |
SYMBOL | PARAMETER | CONDITIONS | VSUPPLY | MIN TYP MAX | UNITS |
VOS | Input Offset Voltage | 15V 5V 2.5V | 0.8 0.8 1.0 | mV mV mV | |
Input VOS Drift | (Note 6) | 2.5V to 15V | 3 8 | V/C | |
IOS | Input Offset Current | 2.5V to 15V | 20 | nA | |
IB | Input Bias Current | 2.5V to 15V | 75 | nA |
SYMBOL | PARAMETER | CONDITIONS | VSUPPLY | MIN | TYP MAX | UNITS |
CMRR | Common Mode Rejection Ratio | VCM = 12V VCM = 2.5V VCM = 0.5V | 15V 5V 2.5V | 78 77 67 | dB dB dB | |
PSRR | Power Supply Rejection Ratio | VS = 2.5V to 15V | 89 | dB | ||
AVOL | Large-Signal Voltage Gain | VOUT = 12V, RL = 5k VOUT = 10V, RL = 2k | 15V 15V 5V 5V 5V 2.5V | 25 20 20 15 10 15 | V/mV V/mV V/mV V/mV V/mV V/mV | |
VOUT = 2.5V, RL = 5k | ||||||
VOUT = 2 .5V, RL = 2k | ||||||
VOUT = 2.5V, RL = 1k | ||||||
VOUT = 1V, RL = 5k | ||||||
VOUT | Output Swing | RL = 5k, VIN = 10mV RL = 2k, VIN = 10mV | 15V 15V 15V 5V 5V 2.5V | 13.4 13.3 12.0 3.4 3.3 1.2 | V V V V V V | |
RL = 1k, VIN = 10mV | ||||||
RL = 1k, VIN = 10mV | ||||||
RL= 500, VIN = 10mV | ||||||
RL = 5k, VIN = 10mV | ||||||
IOUT | Output Current | VOUT = 12V VOUT = 3.3V | 15V 5V | 12.0 6.6 | mA mA | |
ISC | Short-Circuit Current | VOUT = 0V, VIN = 3V | 15V | 24 | mA | |
SR | Slew Rate | AV = – 1, RL = 5k (Note 4) | 15V | 100 | V/s | |
5V | 21 | V/s | ||||
GBW | Gain Bandwidth | f = 200kHz, RL = 10k | 15V | 1.8 | MHz | |
5V | 1.6 | MHz | ||||
Channel Separation | VOUT = 10V, RL = 2k | 15V | 100 | dB | ||
IS | Supply Current | Each Amplifier | 15V | 350 | A | |
Each Amplifier | 5V | 330 | A |
SYMBOL | PARAMETER | CONDITIONS | VSUPPLY | MI | N TYP | MAX | UNITS |
VOS | Input Offset Voltage | 15V 5V | 1.0 1.0 | mV mV | |||
2.5V | 1.2 | mV | |||||
Input VOS Drift | (Note 6) | 2.5V to 15V | 3 | 8 | V/C | ||
IOS | Input Offset Current | 2.5V to 15V | 50 | nA | |||
IB | Input Bias Current | 2.5V to 15V | 100 | nA | |||
CMRR | Common Mode Rejection Ratio | VCM = 12V | 15V 5V 2.5V | 76 76 66 | dB dB dB | ||
VCM = 2.5V | |||||||
VCM = 0.5V | |||||||
PSRR | Power Supply Rejection Ratio | VS = 2.5V to 15V | 87 | dB | |||
AVOL | Large-Signal Voltage Gain | VOUT = 12V, RL = 5k VOUT = 10V, RL = 2k | 15V 15V 5V 5V 5V 2.5V | 20 15 15 10 8 10 | V/mV V/mV V/mV V/mV V/mV V/mV | ||
VOUT = 2.5V, RL = 5k | |||||||
VOUT = 2 .5V, RL = 2k | |||||||
VOUT = 2.5V, RL = 1k | |||||||
VOUT = 1V, RL = 5k |
SYMBOL | PARAMETER | CONDITIONS | VSUPPLY | MIN | TYP MAX | UNITS |
VOUT | Output Swing | RL = 5k, VIN = 10mV RL = 2k, VIN = 10mV | 15V 15V 15V 5V 5V 2.5V | 13.3 13.2 10.0 3.3 3.2 1.1 | V V V V V V | |
RL = 1k, VIN = 10mV | ||||||
RL = 1k, VIN = 10mV | ||||||
RL= 500, VIN = 10mV | ||||||
RL = 5k, VIN = 10mV | ||||||
IOUT | Output Current | VOUT = 10V VOUT = 3.2V | 15V 5V | 10.0 6.4 | mA mA | |
ISC | Short-Circuit Current | VOUT = 0V, VIN = 3V | 15V | 20 | mA | |
SR | Slew Rate | AV = – 1, RL = 5k (Note 4) | 15V | 50 | V/s | |
5V | 15 | V/s | ||||
GBW | Gain Bandwidth | f = 200kHz, RL = 10k | 15V | 1.6 | MHz | |
5V | 1.4 | MHz | ||||
Channel Separation | VOUT = 10V, RL = 2k | 15V | 99 | dB | ||
IS | Supply Current | Each Amplifier | 15V | 380 | A | |
Each Amplifier | 5V | 350 | A |
Note 2: Differential inputs of 10V are appropriate for transient operation only, such as during slewing. Large, sustained differential inputs will cause excessive power dissipation and may damage the part. See Input Considerations in the Applications Information section of this data sheet for more details.
Note 4: Slew rate is measured between 8V on the output with 12V
input for 15V supplies and 2V on the output with 3V input for 5V supplies.
Note 5: Full-power bandwidth is calculated from the slew rate measurement: FPBW = (Slew Rate)/2VP.
Note 7: The LT1352C/LT1353C are guaranteed to meet specified performance from 0C to 70C. The LT1352C/LT1353C are designed, characterized and expected to meet specified performance from
– 40C to 85C but are not tested or QA sampled at these temperatures. The LT1352I/LT1353I are guaranteed to meet specified performance from – 40C to 85C.
SUPPLY CURRENT PER AMPLIFIER (A)
350
300
250
125C
V+
– 0.5
COMMON MODE RANGE (V)
–1.0
–1.5
–2.0
TA = 25C VS = 15V | ||||||
IB = | I + + I – B B 2 | |||||
30
INPUT BIAS CURRENT (nA)
20
10
–55C
25C
200
150
100
0
5 10 15 20
2.0
TA = 25C | |||
VOS = 1mV | |||
1.5
1.0
0.5
V–
0
5 10
15 20
0
–10
–20
–15
–10 –5 0 5
10 15
SUPPLY VOLTAGE (V)
1352/53 G01
SUPPLY VOLTAGE (V)
1352/53 G02
INPUT COMMON MODE VOLTAGE (V)
1352/53 G03
VS = 15V | ||||||
IB = | I + + I – B B 2 | |||||
40
36
INPUT BIAS CURRENT (nA)
32
28
24
20
16
12
8
4
0
100
INPUT VOLTAGE NOISE (nV/Hz)
10
1
TA = 25C VS = 15V AV = 101 RS = 100k
en
in
10
1
0.1
110
INPUT CURRENT NOISE (pA/Hz)
OPEN-LOOP GAIN (dB)
100
90
80
70
60
TA = 25C
VS = 15V
VS = 5V
–50
–25 0
25 50 75
100 125
1 10 100
1k 10k
10 100 1k 10k
TEMPERATURE (C)
1352/53 G04
FREQUENCY (Hz)
1352/53 G05
LOAD RESISTANCE ()
1352/53 G06
100
V+
V+
– 0.5
VS = 5V
85C
OUTPUT VOLTAGE SWING (V)
VS = 15V VO = 12V RL = 5k | ||||||
99 –1
OPEN-LOOP GAIN (dB)
–2
98
–3
97
3
TA = 25C VIN = 10mV
RL = 1k
RL = 2k
–1.0
OUTPUT VOLTAGE SWING (V)
–1.5
–2.0
2.0
VIN = 10mV
25C
85C
25C
–40C
25C
–40C 85C
96
95
94
–50
–25 0
25 50
75 100 125
2
1
V–
0 5 10
RL = 1k RL = 2k
15 20
1.5 –40C
1.0
0.5
V–
–20 –15
–10
–40C
25C
85C
– 5 0 5
10 15 20
TEMPERATURE (C)
1352/53 G07
SUPPLY VOLTAGE (V)
1352/53 G08
OUTPUT CURRENT (mA)
1352/53 G09
OUTPUT SHORT-CIRCUIT CURRENT (mA)
VS = 15V | ||||||
SINK | ||||||
SOURCE | ||||||
60
55
50
45
40
35
30
25
10
8
6
OUTPUT STEP (V)
4
2
0
–2
–4
–6
–8
–10
10mV | 1mV | |||||||
1 | 0mV | 1mV | VS = 15V AV = 1 OUTPUT FILTER: 1.6MHz LPF | |||||
10
8
6
OUTPUT STEP (V)
4
2
0
–2
–4
–6
–8
–10
10mV | 1mV | ||||||||
10mV | 1mV | ||||||||
VS = 15V AV = –1 RG = RF = 2k CF = 5pF RL = 2k | |||||||||
–50
–25 0
25 50
75 100 125
0.7 0.8
0.9 1
1.1 1.2
1.3 1.4 1.5
1.6
0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5
TEMPERATURE (C)
SETTLING TIME (s)
SETTLING TIME (s)
1352/53 G10
1352/53 G11
1352/53 G12
70
TA = 25C
120
1000
TA = 25C
10
OUTPUT IMPEDANCE ()
8 TA = 25C
60 PHASE
50
VS = 15V
AV = –1
RF = RG = 5k
PHASE (DEG)
VS = 15V
100
80
100
VS = 15V
AV = 100
AV = 10 AV = 1
VS = 15V
6 AV = –1
4 RFB = RG = 5k C = 500pF
C = 100pF
C = 5000pF
C = 1000pF
GAIN (dB)
40
30
20
10
0
–10
VS = 5V VS = 5V GAIN
60
40
20
0
–20
–40
10
1
0.1
0.01
2
GAIN (dB)
0
–2
–4
–6
–8
–10
C = 10pF
1k 10k 100k 1M FREQUENCY (Hz)
10M
100M
1k 10k
100k 1M 10M FREQUENCY (Hz)
10k
100k 1M 10M FREQUENCY (Hz)
4.50
4.25
GAIN BANDWIDTH (MHz)
4.00
3.75
3.50
3.25
3.00
2.75
1352/53 G13
50
VS = 15V 48
VS = 5V 46
PHASE MARGIN (DEG)
PHASE MARGIN 44
42
GAIN BANDWIDTH 40
38
VS = 15V 36
5
TA = 25C
4 AV = 1
3 RL = 5k
2
GAIN (dB)
1
0
–1
–2 15V
1352/53 G14
5
TA = 25C
4 AV = –1
3 RF = RG = 5k
2
GAIN (dB)
1
0
–1
–2
1352/53 G15
2.50
2.25
2.00
VS = 5V
34 –3
32 –4
30 –5
5V
2.5V 3
–4
–5
15V
5V
2.5V
–50
–25 0
25 50 75
100 125
10k
100k 1M 10M
10k
100k 1M 10M
TEMPERATURE (C)
1352/53 G16
FREQUENCY (Hz)
1352/53 G17
FREQUENCY (Hz)
1352/53 G18
4.50
4.25
GAIN BANDWIDTH (MHz)
4.00
3.75
3.50
3.25
3.00
2.75
2.50
2.25
2.00
TA = 25C | |||
PHASE MARGIN | |||
GAIN BANDWIDTH | |||
50
48
46
44
42
40
38
36
34
32
30
120
POWER SUPPLY REJECTION RATIO (dB)
100
PHASE MARGIN (DEG)
80
60
40
20
0
COMMON MODE REJECTION RATIO (dB)
TA = 25C VS = 15V | |||||
– PSRR = +PSRR | |||||
120
100
80
60
40
20
0
TA = 25C VS = 15V
0 5 10 15 20
10 100 1k 10k 100k
1M 10M
100
1k 10k 100k 1M
10M
SUPPLY VOLTAGE (V)
FREQUENCY (Hz)
FREQUENCY (Hz)
1352/53 G19
1352/53 G20
1352/53 G21
13523fa
200
TA = 25C
250
TA = 25C VS = 15V AV = –1 RFB = RG = 5k SR = (SR+ + SR–)/2 | ||||||
AV = –1 200
SLEW RATE (V/s)
150
100
50
0
AV = –1
RF = RG = 5k
SR = (SR+ + SR–)/2
200
SLEW RATE (V/s)
150
100
50
0
VS = 15V
VS = 5V
RF = RG = RL = 5k SR = (SR+ + SR–)/2
175
SLEW RATE (V/s)
150
125
100
75
50
25
0
0 5 10 15
–50 –25 0
25 50 75
100 125
0 4 8
12 16
20 24
SUPPLY VOLTAGE (V)
1
TOTAL HARMONIC DISTORTION (%)
TA = 25C VS = 15V
1352/53 G22
TEMPERATURE (C)
30
1352/53 G23
AV = –1
INPUT LEVEL (VP-P)
10
9
1352/53 G24
0.1
0.01
0.001
RL = 5k
VO = 2VP-P
AV = –1
AV = 1
25
OUTPUT VOLTAGE (VP-P)
20
15
10
5 VS = 15V RL = 5k THD = 1%
0
AV = 1
8
AV = 1
OUTPUT VOLTAGE (VP-P)
7
AV = –1
6
5
4
3
2 VS = 5V
1 RL = 5k THD = 1%
0
10 100 1k 10k 100k FREQUENCY (Hz)
1352/53 G25
10k
100k 1M
FREQUENCY (Hz)
1352/53 G26
10k
100k 1M
FREQUENCY (Hz)
1352/53 G27
–30
HARMONIC DISTORTION (dB)
–40
–50
–60
–70
–80
–90
VS = 15V AV = 1 RL = 5k VO = 2VP-P | ||||||||
3RD HARMONIC | ||||||||
2ND HARMONIC | ||||||||
– 40
–50
CROSSTALK (dB)
–60
–70
–80
–90
–100
–110
–120
TA = 25C AV = 1 RL = 1k VIN = 15dBm | |||||||||||||
100
90
80
OVERSHOOT (%)
70
60
50
40
30
20
10
0
TA = 25C VS = 15V RL = 5k | ||||||||||||||
AV = 1 | ||||||||||||||
AV = –1 | ||||||||||||||
100k
FREQUENCY (Hz)
1M
1352/53 G28
100
1k 10k 100k FREQUENCY (Hz)
1M 10M
1352/53 G29
10p
100p 1n 10n 0.1 1 CAPACITIVE LOAD (F)
1352/53 G30
1352/53 G31
1352/53 G32
1352/53 G33
1352/53 G34
1352/53 G35
1352/53 G36
The LT1352/LT1353 amplifiers are easy to use and toler- ant of less than ideal layouts. For maximum performance (for example, fast 0.01% settling) use a ground plane, short lead lengths and RF-quality bypass capacitors (0.01F to 0.1F). For high drive current applications use low ESR bypass capacitors (1F to 10F tantalum).
The parallel combination of the feedback resistor and gain setting resistor on the inverting input can combine with the input capacitance to form a pole which can cause peaking or even oscillations. If feedback resistors greater than 10k are used, a parallel capacitor of value, CF >
(RG)(CIN/RF), should be used to cancel the input pole and
optimize dynamic performance. For applications where
the DC noise gain is one and a large feedback resistor is used, CF should be greater than or equal to CIN. An example would be an I-to-V converter as shown in the Typical Applications section.
The LT1352/LT1353 are stable with any capacitive load. As the capacitive load increases, both the bandwidth and phase margin decrease so there will be peaking in the frequency domain and in the transient response. Graphs of Frequency Response vs Capacitive Load, Capacitive Load Handling and the transient response photos clearly show these effects.
Each of the LT1352/LT1353 inputs is the base of an NPN and a PNP transistor whose base currents are of opposite polarity and provide first-order bias current cancellation. Because of variation in the matching of NPN and PNP beta, the polarity of the input bias current can be positive or negative. The offset current does not depend on NPN/PNP beta matching and is well controlled. The use of balanced source resistance at each input is recommended for
13523fa
applications where DC accuracy must be maximized. The inputs can withstand transient differential input voltages upto 10Vwithoutdamageandneednoclampingorsource resistance for protection. Differential inputs, however, generate large supply currents (tens ofmA) as required for high slew rates. If the device is used with sustained differential inputs, the average supply current will in- crease, excessivepowerdissipation will result andthepart may be damaged. The part should not be used as a comparator, peak detector or other open-loop applica- tion with large, sustained differential inputs. Under normal, closed-loop operation, an increase of power dis- sipation is only noticeable in applications with large slewing outputs and is proportional to the magnitude of the differential input voltage and the percent of time that the inputs are apart. Measure the average supply current for the application in order to calculate the power dissipation.
The LT1352/LT1353 circuit topology is a true voltage feedback amplifier that has the slewing behavior of a current feedback amplifier. The operation of the circuit can be understood by referring to the Simplified Schematic.
The inputs are buffered by complementary NPN and PNP emitter followers which drive R1, a 1k resistor. The input voltage appears across the resistor generating currents which are mirrored into the high impedance node and compensation capacitor CT. Complementary followers
form an output stage which buffers the gain node from the
load. The output devices Q19 and Q22 are connected to form a composite PNP and a composite NPN.
The bandwidth is set by the input resistor and the capaci- tance on the high impedance node. The slew rate is determined by the current available to charge the high impedance node capacitance. This current is the differen- tial input voltage divided by R1, so the slew rate is proportional to the input. Highest slew rates are therefore seen in the lowest gain configurations. For example, a 10V output step in a gain of 10 has only a 1V input step whereas the same output step in unity gain has a 10 times greater
input step. The graph Slew Rate vs Input Level illustrates this relationship. In higher gain configurations the large- signal performance and the small-signal performance both look like a single pole response.
Capacitive load compensation is provided by the RC, CC network which is bootstrapped across the output stage. When the amplifier is driving a light load the network has no effect. When driving a capacitive load (or a low value
resistive load) the network is incompletely bootstrapped and adds to the compensation at the high impedance node. The added capacitance slows down the amplifier and a zero is created by the RC combination, both of which improve the phase margin. The design ensures that even for very large load capacitances, the total phase lag can never exceed 180 degrees (zero phase margin) and the amplifier remains stable.
The LT1352/LT1353 combine high speed and large output drive in small packages. Because of the wide supply voltage range, it is possible to exceed the maximum junction temperature of 150C under certain conditions. Maximum junction temperature TJ is calculated from the ambient temperature TA and power dissipation PD as follows:
LT1352CN8: TJ = TA + (PD)(130C/W) LT1352CS8: TJ = TA + (PD)(190C/W) LT1353CS: TJ = TA + (PD)(150C/W)
Worst-case power dissipation occurs at the maximum supply current and when the output voltage is at 1/2 of either supply voltage (or the maximum swing if less than 1/2 supply voltage). For each amplifier PD(MAX) is:
PD(MAX) = (V+ – V–)(IS(MAX)) + (V+/2)2/RL or
(V+ – V–)(IS(MAX)) + (V+ – VMAX)(IMAX)
Example: LT1353 in S14 at 85C, VS = 15V, RL = 500, VOUT = 5V (10mA)
PD(MAX) =(30V)(380A)+(15V– 5V)(10mA)= 111mW TJ = 85C + (4)(111mW)(150C/W) = 152C
V+
Q10
Q11
Q12
R2
C1 Q20
R3 Q21
Q7 R1
Q9
Q3
Q17
R6
Q19
CC
–IN
V–
Q5 Q6
1k
Q8 Q4
Q2 Q1
Q14
+IN
Q13
CT
Q15
RC
Q18
R7
Q16
C2
Q23
Q22
R4
Q24 R5
OUTPUT
1352/53 SS
5k
12
DAC
INPUTS
10pF
–
1/2
565A TYPE
A
VOS + IOS (5k) + VOUT < 0.5LSB
VOL
LT1352
+
5k
VOUT
1352/53 TA03
1N5712
10k
BPV22NF
1.5k
–
1/2
LT1352
+
10k
VOUT
10nF
1/2
–
+
LT1352
10nF
10k
1352/53 TA05
(Reference LTC DWG # 05-08-1510)
5 .015* 77 0.381) | (10.160) MAX | ||||||||
8 | 7 | 6 | 5 | ||||||
1 | 2 | 3 | 4 |
.400*
.25 (6.4
.300 – .325
(7.620 – 8.255)
.045 – .065
(1.143 – 1.651)
.130 .005
(3.302 0.127)
NOTE:
.008 – .015
(0.203 – 0.381)
–.015
.325 +.035
–0.381
8.255 +0.889
INCHES
.065
(1.651) TYP
.100 (2.54)
BSC
.120
(3.048) MIN
.018 .003
(0.457 0.076)
.020
(0.508) MIN
N8 1002
DIMENSIONS ARE MILLIMETERS
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm)
(Reference LTC DWG # 05-08-1610)
.050 BSC
.045 .005
.189 – .197
(4.801 – 5.004)
NOTE 3
8 7 6 5
.245
MIN
.160 .005
.228 – .244
(5.791 – 6.197)
.150 – .157
(3.810 – 3.988)
NOTE 3
.030 .005
TYP
RECOMMENDED SOLDER PAD LAYOUT
.010 – .020 45
(0.254 – 0.508)
.008 – .010
(0.203 – 0.254)
0– 8 TYP
1 2 3 4
.053 – .069
(1.346 – 1.752)
.004 – .010
(0.101 – 0.254)
NOTE:
.016 – .050
(0.406 – 1.270)
INCHES
.014 – .019
(0.355 – 0.483) TYP
.050
(1.270) BSC
DIMENSIONS IN (MILLIMETERS)
DRAWING NOT TO SCALE
THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm)
SO8 0303
(Reference LTC DWG # 05-08-1610)
.050 BSC
.045 .005
.337 – .344
(8.560 – 8.738)
NOTE 3
N
14 13 12 11 10 9 8
.245
MIN
1
.030 .005
.160 .005
2
3
N/2
N
.228 – .244
(5.791 – 6.197)
.150 – .157
(3.810 – 3.988)
NOTE 3
N/2
TYP
RECOMMENDED SOLDER PAD LAYOUT
1
2 3 4
5 6 7
.010 – .020 45
(0.254 – 0.508)
.008 – .010
(0.203 – 0.254)
0 – 8 TYP
.053 – .069
(1.346 – 1.752)
.004 – .010
(0.101 – 0.254)
NOTE:
.016 – .050
(0.406 – 1.270)
INCHES
.014 – .019
(0.355 – 0.483) TYP
.050
(1.270) BSC
S14 0502
DIMENSIONS IN (MILLIMETERS)
DRAWING NOT TO SCALE
THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm)
Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen- tation that the interconnection of its circuits asdescribedherein will not infringe on existing patent rights.
13523fa
15
VIN
4.64k
13.3k
4.64k
–
470pF
1/2
5.49k
11.3k
5.49k
220pF
2200pF
LT1352
+
4700pF
–
1/2
LT1352
+
VOUT
1352/53 TA04
RELATED PARTS
PART NUMBER | DESCRIPTION | COMMENTS |
LT1351 | 250A, 3MHz, 200V/s Op Amp | Good DC Precision, C-Load Stable, Power Saving Shutdown |
LT1354/55/56 | Single/Dual/Quad 1mA, 12MHz, 400V/s Op Amp | Good DC Precision, Stable with All Capacitive Loads |
16
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com
13523fa LT/TP 0603 1K REV A • PRINTED IN USA
LINEAR TECHNOLOGY CORPORATION 1996
Mouser Electronics
Authorized Distributor
Click to View Pricing, Inventory, Delivery & Lifecycle Information:
Analog Devices Inc.:
LT1352IS8#PBF LT1353CS#TRPBF LT1353CS LT1353CS#PBF LT1352CS8#PBF LT1352IN8 LT1352IN8#PBF LT1352IS8 LT1353CS#TR LT1352CS8#TR LT1352IS8#TRPBF LT1352CN8 LT1352IS8#TR LT1352CS8#TRPBF LT1352CS8 LT1352CN8#PBF