BQ25570_14 Datasheet, PDF (8/41 Pages) Texas Instruments – Ultra Low Power Harvester Power Management IC with Boost Charger, and Nano-Powered Buck Converter

bq25570
SLUSBH2C – MARCH 2013 – REVISED JANUARY 2014
DEVICE INFORMATION
RGT PACKAGE
(TOP VIEW)
20 19 18 17 16
VSS ¹
VIN_DC ²
VOC_SAMP ³
VREF_SAMP ⁴
EN 5
bq25570
RGR
3.5x3.5mm
15 _VSS
14 _VOUT
13 _{VBAT_OK}
12 _{VOUT_SET}
11 _{OK_PROG}
6
7
8
9 10
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Figure 1. bq25570 3.5mm x 3.5mm QFN-20 Package
PIN
NO.
NAME
1
VSS
2
VIN_DC
3
VOC_SAMP
4
VREF_SAMP
5
EN
6
VOUT_EN
7
VBAT_OV
8
VRDIV
9
NC
10
OK_HYST
11
OK_PROG
12
VOUT_SET
13
VBAT_OK
14
VOUT
15
VSS
16
LBUCK
I/O TYPE
Input
Input
Input
Input
Iinput
Input
Input
Output
Input
Input
Input
Input
Output
Output
Supply
I/O
PIN FUNCTIONS
DESCRIPTION
Power ground for the boost charger.
DC voltage input from energy harvesting source. Connect at least a 4.7 µF capacitor as
close as possible between this pin and pin 1.
Sampling pin for MPPT network. Connect to VSTOR to sample at 80% of input source
open circuit voltage. Connect to GND for 50% or connect to the mid-point of external
resistor divider between VIN_DC and GND.
Sample and hold circuit output for the reference set by the MPPT per VOC_SAMP.
Connect a 0.01 µF capacitor from this pin to GND.
Active low digital programming input for enabling/disabling the IC. Connect to GND to
enable the IC.
Active high digital programming input for enabling/disabling the buck converter. Connect to
VSTOR to enable the buck converter.
Connect to the mid-point of external resistor divider between VRDIV and GND for setting
the VBAT overvoltage threshold.
Connect high side of resistor divider networks to this biasing voltage.
Connect to ground using the IC's PowerPad.
Connect to the mid-point of external resistor divider between VRDIV and GND for setting
the VBAT_OK hystersis threshold.
Connect to the mid-point of external resistor divider between VRDIV and GND for setting
the VBAT_OK threshold.
Connect to the mid-point of external resistor divider between VRDIV and GND for setting
the VOUT regulation set point.
Digital output for battery good indicator. Internally referenced to the VSTOR voltage.
Buck converter output. Connect at least 22 µF output capacitor between this pin and pin 15
(VSS).
Power ground for the buck converter and analog/signal ground for the resistor dividers and
VREF_SAMP capacitor.
Inductor connection for the buck converter switching node. Connect at least a 4.7 µH
inductor between this pin and pin 14 (VOUT).
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