SLUUBW5A July 2018 – September 2021 BQ34Z100-G1
The device supports multiple options for using one to 16 LEDs as an output device to display the remaining state of charge, or, if Pack Configuration C [SOH_DISP] is set, then state-of-health. The LED/COMM Configuration register determines the behavior.
Bit 7 | Bit 6 | Bit 5 | Bit 4 | Bit 3 | Bit 2 | Bit 1 | Bit 0 |
---|---|---|---|---|---|---|---|
EXT_LED3 | EXT_LED2 | EXT_LED1 | EXT_LED0 | LED_ON | LED_Mode2 | LED_Mode1 | LED_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, LED_ON, will cause the LED display to be always on, except in Single LED mode where it is not applicable. 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. The LED Hold Time parameter may be used to configure how long the LED display remains on if LED_ON is clear. LED Hold Time configures the update interval for the LED display if LED_ON 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 RemainingCapacity()or StateOfHealth() 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 where each 1% of RSOC is a 7.8125-ms high time. So, for example, 10% RSOC or SOH will have the LED on for 78.1 ms and off for 921.9 ms. 90% RSOC or SOH will have the LED on for 703.125 ms and off for 296.875 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 or SOH 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 or SOH = 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. 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.