BQ24725A_17 Datasheet, PDF (10/47 Pages) Texas Instruments – 1-4 Cell Li+ Battery SMBus Charge Controller with N-Channel Power MOSFET Selector and Advanced Circuit Protection

bq24725A
SLUSAL0A – SEPTEMBER 2011 – REVISED AUGUST 2014
www.ti.com
6.6 Timing Characteristics
4.5 V ≤ V_VCC ≤ 24 V, 0°C ≤ T_J ≤ 125°C, typical values are at T_A = 25°C, with respect to GND (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN TYP MAX
SMBus TIMING CHARACTERISTICS
t_R
SCLK/SDATA rise time
t_F
SCLK/SDATA fall time
t_W(H)
SCLK pulse width high
t_W(L)
SCLK Pulse Width Low
t_SU(STA)
Setup time for START condition
t_H(STA)
START condition hold time after which first clock pulse is generated
t_SU(DAT)
Data setup time
t_H(DAT)
Data hold time
t_SU(STOP)
Setup time for STOP condition
t_(BUF)
Bus free time between START and STOP condition
F_S(CL)
Clock Frequency
HOST COMMUNICATION FAILURE
t_timeout
SMBus bus release timeout⁽¹⁾
t_BOOT
Deglitch for watchdog reset signal
Watchdog timeout period, ChargeOption() bit [14:13] = 01⁽²⁾
1
300
4
50
4.7
4.7
4
250
300
4
4.7
10
100
25
35
10
35
44
53
t_WDI
Watchdog timeout period, ChargeOption() bit [14:13] = 10⁽²⁾
Watchdog timeout period, ChargeOption() bit [14:13] = 11⁽²⁾ (Default)
70
88
105
140
175
210
UNIT
μs
ns
μs
μs
μs
μs
ns
ns
µs
μs
kHz
ms
ms
s
s
s
(1) Devices participating in a transfer will timeout when any clock low exceeds the 25ms minimum timeout period. Devices that have
detected a timeout condition must reset the communication no later than the 35ms maximum timeout period. Both a master and a slave
must adhere to the maximum value specified as it incorporates the cumulative stretch limit for both a master (10ms) and a slave (25ms).
(2) User can adjust threshold via SMBus ChargeOption() REG0x12.
6.7 Typical Characteristics
,
CH1: VCC, 10V/div, CH2: ACDET 2V/div, CH3: ACOK, 5V/div
CH4: REGN, 5V/div, 40ms/div
Figure 1. VCC, ACDET, REGN and ACOK Power Up
CH1: ILIM, 1V/div
CH4: inductor current 1A/div, 20ms/div
Figure 2. Charge Enable by ILIM
10
Submit Documentation Feedback
Product Folder Links: bq24725A
Copyright © 2011–2014, Texas Instruments Incorporated