SLVSFF4 December 2019 TLVH431B-EP
PRODUCTION DATA.
In order for TLVH431B-EP to properly be used as a comparator, the logic output must be readable by the receiving logic device. This is accomplished by knowing the input high and low level threshold voltage levels, typically denoted by VIH and VIL.
As shown in Figure 30 and Figure 31, TLVH431B-EP's output low level voltage in open-loop/comparator mode is approximately 1 V, which is sufficient for some 3.3-V supplied logic. However, would not work for 2.5-V and 1.8-V supplied logic. To accommodate this a resistive divider can be tied to the output to attenuate the output voltage to a voltage legible to the receiving low-voltage logic device.
TLVH431B-EP's output high voltage is approximately VSUP due to TLVH431B-EP being open-collector. If VSUP is much higher than the receiving logic's maximum input voltage tolerance, the output must be attenuated to accommodate the outgoing logic's reliability.
When using a resistive divider on the output, be sure to make the sum of the resistive divider (R1 and R2 in Figure 29) is much greater than RSUP in order to not interfere with TLVH431B-EP's ability to pull close to VSUP when turning off.