JAJSJM2B July 2022 – April 2024 TPS929240-Q1
PRODUCTION DATA
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The TPS929240-Q1 must have an external resistor R(REF) to set the internal current reference I(REF) as shown in Figure 6-1.
The internal current reference, I(FULL_RANGE), is generated based on the I(REF) multiplied by factor K(REF) to provide the full range current reference for each OUTXn channel. The K(REF) is programmable by 2-bit register REFRANGE with four different options. Use the following equation to calculate the I(FULL_RANGE).
where
The following table lists the recommended resistor values of R(REF) and amplifier ratios of K(REF).
REFRANGE | K(REF) | FULL RANGE CURRENT (mA) | |||
---|---|---|---|---|---|
R(REF) = 6.3kΩ | R(REF) = 8.45kΩ | R(REF) = 12.7kΩ | R(REF) = 31.6kΩ | ||
11b(default) | 512 | 100 | 75 | 50 | 20 |
10b | 256 | 50 | 37.5 | 25 | 10 |
01b | 128 | 25 | 18.75 | 12.5 | 5 |
00b | 64 | 12.5 | 9.375 | 6.25 | 2.5 |
Place the R(REF) resistor as close as possible to the REF pin with an up to 2.2-nF ceramic capacitor in parallel to improve the noise immunity. The off-board R(REF) setup is not allowed due to the concern of instability reference current. TI recommends a 1-nF ceramic capacitor in parallel with R(REF).