Datasheet

LP3972
www.ti.com SNVS468K –SEPTEMBER 2006–REVISED MAY 2013
PIN DESCRIPTIONS (continued)
Pin No. Name I/O Type
(1)
Description
20 V
IN
Buck2 I PWR Battery input power to Buck2
21 SDA I/O D I
2
C Data (Bidirectional)
22 SCL I D I
2
C Clock
23 FB2 I A Buck2 input feedback terminal
24 nRSTO O D Reset output from the PMIC to the processor
25 V
OUT
LDO5 O PWR LDO5 output
26 V
IN
LDO5 I PWR Power input to LDO5, this can be connected to V
IN
or to a separate 1.8V supply.
27 VDDA I PWR Analog Power for VREF, BIAS
28 FB3 I A Buck3 Feedback
29 GPIO1 / I/O D General Purpose I/O / Ext. backup battery charger enable pin. This pin enables
nCHG_EN the main battery / DC source power to charge the backup battery. This pin
toggled via the application processor. By grounding this pin the DC source
continuously charges the backup battery
30 GPIO2 I/O D General Purpose I/O
31 V
IN
Buck3 I PWR Battery input power to Buck3
32 SW3 O PWR Buck3 switcher output
33 PGND3 G G Buck3 NMOS Power Ground
34 BGND1,2,3 G G Bucks 1, 2 and 3 analog Ground
35 SYNC I D Frequency Synchronization: Connection to an external clock signal PLL to
synchronize the PMIC internal oscillator.
Input Digital enable pin for the high voltage power domain supplies. Output from
36 SYS_EN I D the Monahans processor.
Digital enable pin for the Low Voltage domain supplies. Output signal from the
37 PWR_EN I D Monahans processor
38 PGND1 G G Buck1 NMOS Power Ground
39 SW1 O PWR Buck1 Switcher output
40 VIN Buck1 I PWR Battery input power to Buck1
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
Absolute Maximum Ratings
(1)(2)
All Inputs −0.3V to +6.5V
GND to GND SLUG ±0.3V
Junction Temperature (T
J-MAX
) 150°C
Storage Temperature −65°C to +150°C
Power Dissipation (T
A
= 70°C)
(3)
3.2W
Junction-to-Ambient Thermal Resistance θ
JA
(3)
25°C/W
Maximum Lead Temp (Soldering) 260°C
Human Body Model 2 kV
ESD Rating
(4)
Machine Model 200V
(1) Absolute Maximum Ratings are limits beyond which damage to the device may occur. Operating Ratings are conditions under which
operation of the device is specified. Operating Ratings do not imply ensured performance limits. For specified performance limits and
associated test conditions, see the Electrical Characteristics tables.
(2) If Military/Aerospace specified devices are required, please contact the TI Sales Office/Distributors for availability and specifications.
(3) In applications where high power dissipation and/or poor package thermal resistance is present, the maximum ambient temperature may
have to be derated. Maximum ambient temperature (TA-MAX) is dependent on the maximum operating junction temperature (TJ-MAX-
OP = 125°C), the maximum power dissipation of the device in the application (PD-MAX), and the junction-to ambient thermal resistance
of the part/package in the application (θ
JA
), as given by the following equation: TA-MAX = TJ-MAX-OP – (θ
JA
x PD-MAX).
(4) The Human body model is a 100 pF capacitor discharged through a 1.5 kΩ resistor into each pin. (MIL-STD-883 3015.7) The machine
model is a 200 pF capacitor discharged directly into each pin. (EAIJ).
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