Input | Output | Error | Supply | ||||||
---|---|---|---|---|---|---|---|---|---|
ILOAD Min | ILOAD Max | VCM | IOUT Min | IOUT Max | Bandwidth | ILOAD > 45 A | IDD | VS | Vee |
5A | 304A | 12V | 42.1µA | 1.6842mA | 400kHz | 2.1% maximum at full-scale range | N × (2.4mA + 750µA) + IOUT | 5V | GND (0V) |
Design Description
This circuit demonstrates how to convert a voltage-output, current-sense amplifier (CSA) into a current-output circuit using the Howland Current Pump method and operational amplifier (op amp). Furthermore, this circuit demonstrates how to design two separate circuits to measure two separate, but redundant supplies powering one load.
Design Notes
Design Steps
Design Simulations
DC Simulation Results
The following graph shows a linear output response for load currents from 5A to 304A.
AC Simulation Result – ILOAD to IOUT (VOUT) circuit gain
Design References
See Analog Engineer's Circuit Cookbooks for TI's comprehensive circuit library.
Getting Started with Current Sense Amplifiers video series
https://training.ti.com/getting-started-current-sense-amplifiers
Current Sense Amplifiers on TI.com
http://www.ti.com/amplifier-circuit/current-sense/products.html
Comprehensive Study of the Howland Current Pump
For direct support from TI Engineers use the E2E community
Design Featured Current Sense Amplifier
INA240A3 | |
---|---|
VS | 2.7V to 5.5V (operational) |
VCM | –4V to 80V |
Swing to VS (VSP) | VS – 0.2V |
VOS | ±25µV at 12V VCM |
IQ_MAX | 2.4mV |
IIB | 90µA at 12V |
BW | 400kHz |
# of channels | 1 |
Body size (including pins) | 4mm × 3.91mm |
www.ti.com/product/ina240 |
Design Featured Operational Amplifier
TLV9061 (TLV9061S is shutdown version) | |
VS | 1.8V to 5.5V |
VCM | (V–) – 0.1V < VCM < (V+) + 0.1V |
CMRR | 103dB |
AOL | 130dB |
VOS | ±1.6mV maximum |
IQ | 750µA maximum |
IB (input bias current) | ± 0.5pA |
GBP (gain bandwidth product) | 10MHz |
# of channels | 1 (2 and 4 channel packages available) |
Body size (including pins) | 0.80mm × 0.80mm |
www.ti.com/product/tlv9061 |
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