ZHCSL19C May 2019 – June 2021 LM61440
PRODUCTION DATA
Because VOUT = 5 V in this design, the BIAS pin is tied to VOUT to reduce LDO power loss. The output voltage is supplying the LDO current instead of the input voltage. The power saving is ILDO × (VIN – VOUT). The power saving is more significant when VIN >> VOUT and with higher frequency operation. To prevent VOUT noise and transients from coupling to BIAS, a series resistor, 1 Ω to 10 Ω, can be added between VOUT and BIAS. A bypass capacitor with a value of 1 μF or higher can be added close to the BIAS pin to filter noise. Note the maximum allowed voltage on the BIAS pin is 16 V.