NCP1871 Datasheet, PDF (3/27 Pages) ON Semiconductor – Narrow Voltage DC Battery Charger

NCP1871
ACSP
RBDRV
VIN
VSEL
VINOK
20 19 18 17 16
1
15
2
14
3
GND 13
4
12
5
11
6 7 8 9 10
LSDRV
BCSP
BCSN
BATDRV
VBAT
Figure 2. Pin Out Description (Top View)
Table 1. PIN FUNCTIONAL DESCRIPTION
Pin
Name
Type
1
ACSP
ANALOG INPUT
2
RBDRV
ANALOG OUTPUT
3
VIN
4
VSEL
ANALOG INPUT
ANALOG INPUT
5
VINOK
OPEN DRAIN OUTPUT
6
PRHOTB OPEN DRAIN OUTPUT
7
PMO
ANALOG OUTPUT
8
SDA
9
SCL
10
TS
11
VBAT
12 BATDRV
13
BCSN
14
BCSP
15
LSDRV
16
VCORE
17
CBOOT
18
SW
19
HSDRV
DIGITAL IN/OUT
DIGITAL INPUT
ANALOG INPUT
ANALOG IN/OUT
ANALOG OUTPUT
ANALOG INPUT
ANALOG INPUT
ANALOG OUTPUT
ANALOG OUTPUT
ANALOG IN/OUT
ANALOG OUTPUT
ANALOG OUTPUT
20
ACSN
ANALOG INPUT
−
EXPOSE
PAD
GROUND
Description
Charger Adapter Current Sense Positive terminal. Use a 10 mW sense resistor
RAC. Bypass ACSP with a 10 mF capacitor
Reverse Blocking FET Driver. Drives the gate of the RBFET NMOS
Can also drive gate optional ACFET NMOS.
Charger Adapter Input. Bypass with a Damping network
Adapter detection input. Program adapter valid input threshold by connecting a
resistor divider from adapter input to VSEL pin to GND pin. Connect a serial resis-
tance of 220 kW to select 3−4 Cells default setting.
Charge Adapter Valid Output. Signals the VIN is within the target range.
Open drain output requiring an external pull up. Also use for short pulse signal inter-
rupt generation
Processor Hot Signal Output. Pulled low to reduce processor speed based on BCSP.
Current based indication of system power. Amplified version of the adapter power,
the battery power or sum of both.
Control Bus Data Line.
Control Bus Clock Line.
Battery Presence Detection. Connect this pin to the battery thermistor sensor.
Battery Connection. Bypass with at least 10 mF capacitor.
Battery FET Driver.
Battery Current Sense Negative Terminal. Use a 10 mW sense resistor RBC.
Battery Current Sense Positive Terminal. Use a 10 mW sense resistor RBC.
Low Side Switch Driver. Drives the gate of the DC to DC low side NMOS.
Core Voltage. Do not connect load on this pin. Bypass with a 2.2 mF capacitor
Bootstrap Capacitor Connection.
Switching Node. Connection to the 2.2 mH inductor.
High Side Switch Driver. Drives the gate of the DC to DC high side NMOS. Supplied
from the bootstrap capacitor.
Charger Adapter Current Sense Negative terminal.
Use a 10 mW sense resistor RAC.
Internally connected to ground
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