BQ24257 Datasheet, PDF (18/45 Pages) Texas Instruments – 2A Single Input I2C, Standalone Switch-Mode Li-Ion Battery Charger with Integrated Current Sense Resistor

bq24257
bq24258
SLUSBG0B – FEBRUARY 2013 – REVISED JULY 2013
V_BATREG
(3.8V)
V_OVRCHG
(3.7V)
V_FLTCHG
(3.5V)
Trickle
Charge
Pre-
charge
Current Regulation
Phase (CC)
I_CHG
V_CSIN
V_BAT
Discharge
www.ti.com
Float Charge
I_CHG
V_LOWV
V_BATSHRT
I_PRECHG
I_BATSHRT
EN1, EN2, EN3 Pins
If the D+, D- detection pins are not used (bq24257), input current limit pins are available for GPIO control. The
EN1, EN2, and EN3 pins are available in the bq24258 spin to support USB 3.0 compliance. When the input
current limit pins change state, the VIN_DPM threshold changes as well. See Table 1 for details:
Table 1. EN1, and EN2 Truth Table⁽¹⁾
EN3
EN2 EN1 INPUT CURRENT LIMIT
0
0
0 500mA
0
0
1 Externally programmed by ILIM (up to 2.0A)
0
1
0 100mA
0
1
1 Input Hi-Z
1
0
0 900mA
1
0
1 Externally programmed by ILIM (up to 2.0 A)
1
1
0 150mA
1
1
1 Input Hi-Z
VINDPM THRESHOLD
4.36V
Externally programmed VDPM
4.36V
None
4.36V
Externally programmed VDPM
4.36V
None
(1) If EN3 = 0, it will be USB 2.0 compliant; If EN3 = 1, USB 3.0 compliant.
I2C and STAND ALONE OPERATION
The bq24257 series offers a unique feature when compared to traditional host mode chargers—the default input
current limit, output current limit and VIN_DPM parameters can be set via external resistors. In traditional host
mode chargers, the default parameters are programmed during manufacturing to set the i2c registers at a
specific default. If an end application calls for an alternate default setting, the traditional charger is left with the
only option of changing the parameters at the manufacturing stage. This may not always be acceptable.
18
Submit Documentation Feedback
Product Folder Links: bq24257 bq24258
Copyright © 2013, Texas Instruments Incorporated