ZHCSNB8A February 2021 – January 2024 BQ25730
PRODUCTION DATA
To set the output charge voltage, write a 16-bit ChargeVoltage register command (REG0x05/04h()) using the data format listed in Figure 8-18, Table 8-12, and Table 8-13. The charger provides charge voltage range from 1.024 V to 23.000 V, with 8-mV step resolution. Any write below 1.024 V or above 23.000 V is ignored.
Upon POR, ChargeVoltage() is by default set as 4200 mV for 1 s, 8400 mV for 2 s, 12600 mV for 3 s or 16800 mV for 4 s, 21000 mV for 5s. After CHRG_OK goes high, the charge will start when the host writes the charging current to ChargeCurrent() register, the default charging voltage is used if ChargeVoltage() is not programmed. If the battery is different from 4.2 V/cell, the host has to write to ChargeVoltage() before ChargeCurrent() register for correct battery voltage setting. Writing ChargeVoltage() to 0 should keep ChargeVoltage() value unchanged, and force ChargeCurrent() register to zero to disable charge.
The SRN pin senses the battery voltage for voltage regulation and should be connected as close to the battery as possible.
| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| Reserved | Charge Voltage, bit 11 | Charge Voltage, bit 10 | Charge Voltage, bit 9 | Charge Voltage, bit 8 | Charge Voltage, bit 7 | Charge Voltage, bit 6 | Charge Voltage, bit 5 |
| R/W | R/W | R/W | R/W | R/W | R/W | R/W | R/W |
| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| Charge Voltage, bit 4 | Charge Voltage, bit 3 | Charge Voltage, bit 2 | Charge Voltage, bit 1 | Charge Voltage, bit 0 | Reserved | ||
| R/W | R/W | R/W | R/W | R/W | R/W | ||
| LEGEND: R/W = Read/Write; R = Read only; -n = value after reset |
| BIT | FIELD | TYPE | RESET | DESCRIPTION |
|---|---|---|---|---|
| 7 | Reserved | R/W | 0b | Not used. 1 = invalid write. |
| 6 | Charge Voltage, bit 11 | R/W | 0b | 0 = Adds 0 mV of charger voltage. 1 = Adds 16384 mV of charger voltage. |
| 5 | Charge Voltage, bit 10 | R/W | 0b | 0 = Adds 0 mV of charger voltage. 1 = Adds 8192 mV of charger voltage |
| 4 | Charge Voltage, bit 9 | R/W | 0b | 0 = Adds 0 mV of charger voltage. 1 = Adds 4096 mV of charger voltage. |
| 3 | Charge Voltage, bit 8 | R/W | 0b | 0 = Adds 0 mV of charger voltage. 1 = Adds 2048 mV of charger voltage. |
| 2 | Charge Voltage, bit 7 | R/W | 0b | 0 = Adds 0 mV of charger voltage. 1 = Adds 1024 mV of charger voltage. |
| 1 | Charge Voltage, bit 6 | R/W | 0b | 0 = Adds 0 mV of charger voltage. 1 = Adds 512 mV of charger voltage. |
| 0 | Charge Voltage, bit 5 | R/W | 0b | 0 = Adds 0 mV of charger voltage. 1 = Adds 256 mV of charger voltage. |
| BIT | FIELD | TYPE | RESET | DESCRIPTION |
|---|---|---|---|---|
| 7 | Charge Voltage, bit 4 | R/W | 0b | 0 = Adds 0 mV of charger voltage. 1 = Adds 128 mV of charger voltage. |
| 6 | Charge Voltage, bit 3 | R/W | 0b | 0 = Adds 0 mV of charger voltage. 1 = Adds 64 mV of charger voltage. |
| 5 | Charge Voltage, bit 2 | R/W | 0b | 0 = Adds 0 mV of charger voltage. 1 = Adds 32 mV of charger voltage. |
| 4 | Charge Voltage, bit 1 | R/W | 0b | 0 = Adds 0 mV of charger voltage. 1 = Adds 16 mV of charger voltage. |
| 3 | Charge Voltage, bit 0 | R/W | 0b | 0 = Adds 0 mV of charger voltage. 1 = Adds 8 mV of charger voltage. |
| 2-0 | Reserved | R/W | 000b | Not used. Value Ignored. |