LT1970
500mA Power Op Amp with
Adjustable Precision Current Limit
Fea T Descrip T
n
500mA Minimum Output Current
The LT 1970 is a 500mA power op amp with precise
n
Independent Adjustment of Source and
externally controlled current limiting. Separate control
Sink Current Limits
voltages program the sourcing and sinking current limit
n
2% Current Limit Accuracy
sense thresholds with 2% accuracy. Output current may
n
Operates with Single or Split Supplies
be boosted by adding external power transistors.
n
Shutdown/Enable Control Input
The circuit operates with single or split power supplies
n
Open Collector Status Flags:
from 5V to 36V total supply voltage. In normal operation,
Sink Current Limit
the input stage supplies and the output stage supplies are
Source Current Limit
+
connected (V to V and V to V ). To reduce power
CC EE
Thermal Shutdown
+
dissipation it is possible to power the output stage (V ,
n
Fail Safe Current Limit and Thermal Shutdown
V ) from independent, lower voltage rails. The amplifier is
n
1.6V/s Slew Rate
unity-gain stable with a 3.6MHz gain bandwidth product
n
3.6MHz Gain Bandwidth Product
and slews at 1.6V/s. The current limit circuits operate
n
Fast Current Limit Response: 2MHz Bandwidth
with a 2MHz response between the VC or VC control
SRC SNK
n
Specified Temperature Range: 40C to 85C
inputs and the amplifier output.
n
Available in a 20-Lead TSSOP Package
Open collector status flags signal current limit circuit
activation, as well as thermal shutdown of the amplifier.
a T
An enable logic input puts the amplifier into a low power,
n high impedance output state when pulled low. Thermal
Automatic Test Equipment
n shutdown and a 800mA fixed current limit protect the
Laboratory Power Supplies
n chip under fault conditions.
Motor Drivers
n
Thermoelectric Cooler Driver
The LT1970 is packaged in a 20-lead TSSOP package with
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
a thermally conductive copper bottom plate to facilitate
Technology Corporation. All other trademarks are the property of their respective owners.
heat sinking.
Typical a T
A = 2 Amplifier with Adjustable 500mA Full-Scale Current Limited Sinewave Into 10 Load
V
Current Limit and Fault Indication
V
LIMIT
0V TO 5V
15V
15V
4V
V 3k
LIMIT
I =
OUT(LIMIT)
V
CC
10 R 2V
CS +
V
EN
0V
V
LOAD
VC
SRC
V +IN
IN
VC
SNK
2V
R
CS
ISNK
1
I
ISRC OUT
1/4W
TSD
LT1970 OUT
+
SENSE
SENSE
V LOAD
R1 VC = 4V 20s/DIV 1970 TA02
SRC
IN
V
EE
10k VC = 2V
SNK
COMMON
R = 1
CS
R2
10k
15V
1970 TA01
1970fe
1
For more information www.linear.com/LT1970
ion pplica
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a Te Maxi Mu M r a T p in c F T
(Note 1)
TOP VIEW
Supply Voltage (V to V ) ..................................... 36V
CC EE
+
V 1 20 V
EE EE
Positive High Current Supply (V ) ................... V to V
CC
+
+ V 2 19 V
21
Negative High Current Supply(V ) ....................V to V
EE
OUT 3 18 TSD
+
Amplifier Output (OUT) ..................................... V to V
+
SENSE 4 17 ISNK
Current Sense Pins
FILTER 5 16 ISRC
+ +
+
(SENSE , SENSE , FILTER) ........................... V to V
SENSE 6 15 ENABLE
Logic Outputs (ISRC, ISNK, TSD) ....... COMMON to V
CC
V 7 14 COMMON
CC
Input Voltage (IN, +IN) ............ V 0.3V to V + 36V
EE EE
IN 8 13 VC
SRC
Input Current......................................................... 10mA
+IN 9 12 VC
SNK
Current Control Inputs
V 10 11 V
EE EE
(VC , VC ) .............. COMMON to COMMON + 7V
SRC SNK
FE PACKAGE
20-LEAD PLASTIC TSSOP
Enable Logic Input .............................. COMMON to V
CC
T = 150C, = 40C/W (NOTE 8)
JMAX JA
COMMON ....................................................... V to V
EE CC
EXPOSED PAD (PIN 21) IS CONNECTED TO V
EE
Output Short-Circuit Duration ......................... Indefinite
Operating Temperature Range (Note 2)....40C to 85C
Specified Temperature Range (Note 3) .... 40C to 85C
Maximum Junction Temperature.......................... 150C
Storage Temperature Range ...................65C to 150C
Lead Temperature (Soldering, 10 sec) .................. 300C
o r Der i n F Ma T
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION SPECIFIED TEMPERATURE RANGE
LT1970CFE#PBF LT1970CFE#TRPBF LT1970CFE 20-Lead Plastic TSSOP 0C to 70C
LT1970IFE#PBF LT1970IFE#TRPBF LT1970IFE 20-Lead Plastic TSSOP 40C to 85C
Consult LTC Marketing for parts specified with wider operating temperature ranges.
For more information on lead free part marking, go to: