ZHCSD85F August 2012 – November 2018 DS125BR800
PRODUCTION DATA.
The 4-level input pins use a resistor divider to help set the 4 valid levels and provide a wider range of control settings when ENSMB=0. There is an internal 30-kΩ pullup and a 60-kΩ pulldown connected to the package pin. These resistors, together with the external resistor connection combine to achieve the desired voltage level. Using the 1-kΩ pullup, 1-kΩ pulldown, no connect, and 20-kΩ pulldown provide the optimal voltage levels for each of the four input states.
| LEVEL | SETTING | 3.3-V MODE | 2.5-V MODE |
|---|---|---|---|
| 0 | Tie 1 kΩ to GND | 0.10 V | 0.08 V |
| R | Tie 20 kΩ to GND | 1/3 x VIN | 1/3 x VDD |
| Float | Float (leave pin open) | 2/3 x VIN | 2/3 x VDD |
| 1 | Tie 1 kΩ to VDD | VIN - 0.05 V | VDD - 0.04 V |
To minimize the startup current associated with the integrated 2.5-V regulator the 1-kΩ pullup and pulldown resistors are recommended. If several 4-level inputs require the same setting, it is possible to combine two or more 1-kΩ resistors into a single lower value resistor. For example, combining two inputs with a single 500-Ω resistor is a good way to save board space.