INA169

INA169

Other INA169s

––

––

1N4148

Digital I/O on the ADS7870 provides power to

select the desired INA169. Diodes prevent

output current of an

on INA169 from flowing

into an

off INA169.

REF

V+

V+

R

L

Serial

I/O

ADS7870

Clock

Divider

Oscillator

BUF

OUT

BUF

IN

REF

OUT

12-Bit

A/D

Converter

BUF

MUX

Digital

I/O

PGIA

5 V

Copyright © 2017, Texas Instruments Incorporated

18

INA139, INA169

SBOS181F – DECEMBER 2000 – REVISED FEBRUARY 2017

www.ti.com

Product Folder Links: INA139 INA169

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Copyright © 2000–2017, Texas Instruments Incorporated

Typical Applications (continued)

8.2.6 Multiplexed Measurement Using Logic Signal for Power

Multiple loads can be measured as illustrated in Figure 18. In this configuration, each INA139 or INA169 device

is powered by the digital I/O from the ADS7870. Multiplex each device by switching the desired I/O on or off.

Figure 18. Multiplexed Measurement Using Logic Signal for Power

9 Power Supply Recommendations

The input circuitry of the INA139 can accurately measure beyond the power-supply voltage (V+). For example,

the V+ power supply can be 5 V, whereas the load power supply voltage is up to 40 V (or 60 V with the INA169).

However, the output voltage range of the OUT terminal is limited by the lesser of the two voltages (see the

Output Voltage Range section). TI recommends placing a 0.1-µF capacitor near the V+ pin on the INA139 or

INA169. Additional capacitance may be required for applications with noisy supply voltages.