LT1970_15 Datasheet, PDF (1/26 Pages) Linear Technology – 500mA Power Op Amp with Adjustable Precision Current Limit

LT1970
500mA Power Op Amp with
Adjustable Precision Current Limit
FEATURES
DESCRIPTION
n _{± 500mA Minimum Output Current}
n _{Independent Adjustment of Source and}
Sink Current Limits
n _{2% Current Limit Accuracy}
n _{Operates with Single or Split Supplies}
n _{Shutdown/Enable Control Input}
n _{Open Collector Status Flags:}
Sink Current Limit
Source Current Limit
Thermal Shutdown
n _{Fail Safe Current Limit and Thermal Shutdown}
n _{1.6V/µs Slew Rate}
n _{3.6MHz Gain Bandwidth Product}
n _{Fast Current Limit Response: 2MHz Bandwidth}
n _{Specified Temperature Range: –40°C to 85°C}
n _{Available in a 20-Lead TSSOP Package}
APPLICATIONS
n _{Automatic Test Equipment}
n _{Laboratory Power Supplies}
n _{Motor Drivers}
n _{Thermoelectric Cooler Driver}
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
The LT^®1970 is a ± 500mA power op amp with precise
externally controlled current limiting. Separate control
voltages program the sourcing and sinking current limit
sense thresholds with 2% accuracy. Output current may
be boosted by adding external power transistors.
The circuit operates with single or split power supplies
from 5V to 36V total supply voltage. In normal operation,
the input stage supplies and the output stage supplies are
connected (V_CC to V⁺ and V_EE to V^–). To reduce power
dissipation it is possible to power the output stage (V⁺,
V^–) from independent, lower voltage rails. The amplifier is
unity-gain stable with a 3.6MHz gain bandwidth product
and slews at 1.6V/µs. The current limit circuits operate
with a 2MHz response between the VC_SRC or VC_SNK control
inputs and the amplifier output.
Open collector status flags signal current limit circuit
activation, as well as thermal shutdown of the amplifier.
An enable logic input puts the amplifier into a low power,
high impedance output state when pulled low. Thermal
shutdown and a ±800mA fixed current limit protect the
chip under fault conditions.
The LT1970 is packaged in a 20-lead TSSOP package with
a thermally conductive copper bottom plate to facilitate
heat sinking.
TYPICAL APPLICATION
A_V = 2 Amplifier with Adjustable ± 500mA Full-Scale
Current Limit and Fault Indication
V_LIMIT
0V TO 5V
15V
15V
I_OUT(LIMIT)
=
±
V_LIMIT
10 • R_CS
V_{CC V+}
3k
EN
V_IN
+IN
VC_SRC
VC_SNK
ISNK
ISRC
TSD
R_CS
I_OUT
1Ω
1/4W
LT1970
OUT
SENSE⁺
SENSE^–
V^–
–IN
V_EE
COMMON
R1 ^LOAD
10k
–15V
R2
10k
1970 TA01
Current Limited Sinewave Into 10Ω Load
4V
2V
V_LOAD 0V
–2V
VC_SRC = 4V
VC_SNK = 2V
R_CS = 1Ω
20µs/DIV
1970 TA02
For more information www.linear.com/LT1970
1970fd
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