ZHCS926C May 2012 – May 2021 BQ34Z100
PRODUCTION DATA
The device supports multiple options for using one to 16 LEDs as an output device to display the remaining state of charge. The LED/COMM Configuration register determines the behavior.
| Bit 7 | Bit 6 | Bit 5 | Bit 4 | Bit 3 | Bit 2 | Bit 1 | Bit 0 |
|---|---|---|---|---|---|---|---|
| XLED3 | XLED2 | XLED1 | XLED0 | LEDON | Mode2 | Mode1 | Mode0 |
Bits 0, 1, 2 are a code for one of five modes. 0 = No LED, 1 = Single LED, 2 = Four LEDs, 3 = External LEDs with I2C comm, 4 = External LEDs with HDQ comm.
Setting Bit 3, LEDON, will cause the LED display to be always on, except in Single LED mode . When clear (default), the LED pattern will only be displayed after holding an LED display button for one to two seconds. The button applies 2.5 V from REG25 pin 7 to VEN pin 2 (refer to Section 8.1). The LED Hold Time parameter may be used to configure how long the LED display remains on if LEDON is clear. LED Hold Time configures the update interval for the LED display if LEDON is set.
Bits 4, 5, 6, and 7 are a binary code for number of external LEDs. Code 0 is reserved. Codes 1 through 15 represents 2~16 external LEDs. So, number of External LEDs is 1 + Value of the 4-bit binary code. Display of Remaining Capacity will be evenly divided among the selected number of LEDs.
Single LED mode—Upon detecting an A/D value representing 2.5 V on the VEN pin, Single LED mode will toggle the LED as duty cycle on within a period of 1 s . So, for example, 10% RSOC will have the LED on for 100 ms and off for 900 ms. 90% RSOC will have the LED on for 900 ms and off for 100 ms. Any value > 90% will display as 90%.
Four-LED mode—Upon detecting an A/D value representing 2.5 V on the VEN pin, Four-LED mode will display the RSOC by driving pins RC2(LED1), RC0(LED2), RA1(LED3),RA2(LED4) in a proportional manner where each LED represents 25% of the remaining state-of-charge. For example, if RSOC = 67%, three LEDs will be illuminated.
External LED mode—Upon detecting an A/D value representing 2.5 V on the VEN pin, External LED mode will transmit the RSOC into an SN74HC164 (for 2–8 LEDs) or two SN74HC164 devices (for 9–16 LEDs) using a bit-banged approach with RC2 as Clock and RC0 as Data (see Figure 8-4). LEDs will be lit for a number of seconds as defined in a data flash parameter. Refer to the SN54HC164, SN74HC164 8-Bit Parallel-Out Serial Shift Registers Data Sheet (SCLS115E) for details on these devices.
Extended commands are available to turn the LEDs on and off for test purposes.