lm26480sqx-bf National Semiconductor Corporation, lm26480sqx-bf Datasheet - Page 4

• Manufacturer Part Number: lm26480sqx-bf
• Description: Lm26480 Externally Programmable Dual High-current Step-down Dc/dc And Dual Linear Regulators
• Manufacturer: National Semiconductor Corporation

www.national.com
LLP Pin No.
Pin Descriptions
A: Analog Pin
VIN+ is the largest potential voltage on the device.
DAP
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
1
2
3
4
5
6
7
8
9
Power Block Input
VINLDO12
AVDD
VIN1
VIN2
VINLDO1
VINLDO2
GND_SW1
GND_SW2
VINLDO12
VINLDO1
VINLDO2
D: Digital Pin
ENLDO2
ENLDO1
ENSW1
ENSW2
GND_C
GND_L
NPOR
Name
SYNC
AVDD
LDO1
LDO2
FBL1
FBL2
SW1
VIN1
VIN2
SW2
DAP
FB1
FB2
G: Ground Pin
GND
I/O
O
G
O
G
O
G
G
O
O
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Enabled
VIN+
VIN+
VIN+
VIN+
≤
≤
VIN+
VIN+
PWR: Power Pin
Power Block Operation
G/(D)
Type
PWR
PWR
PWR
PWR
PWR
PWR
PWR
PWR
PWR
PWR
GND
D
G
D
G
D
G
D
D
G
A
A
A
A
Disabled
VIN+
VIN+
VIN+ or 0V
VIN+ or 0V
≤
≤
Analog Power for Internal Functions (VREF, BIAS, I
Frequency Synchronization pin which allows the user to connect an
external clock signal to synchronize the PMIC internal oscillator.
Default OFF and must be grounded when not used. Part number
LM26480SQ-BF has this feature enabled.
nPOR Power on reset pin for both Buck1 and Buck 2. Open drain logic
output 100K pullup resistor. nPOR is pulled to ground when the
voltages on these supplies are not good. See nPOR section for more
info.
Buck1 NMOS Power Ground
Buck1 switcher output pin
Power in from either DC source or Battery to Buck1
Enable Pin for Buck1 switcher, a logic HIGH enables Buck1. Pin cannot
be left floating.
Buck1 input feedback terminal
Non-switching core ground pin
Analog Power for Buck converters
Buck2 input feedback terminal
Enable Pin for Buck2 switcher, a logic HIGH enables Buck2. Pin cannot
be left floating.
Power in from either DC source or Battery to Buck2
Buck2 switcher output pin
Buck2 NMOS
LDO2 enable pin, a logic HIGH enables LDO2. Pin cannot be left
floating.
LDO1 enable pin, a logic HIGH enables LDO1. Pin cannot be left
floating.
LDO ground
Power in from either DC source or battery to LDO1
LDO1 Output
LDO1 Feedback Terminal
LDO2 Feedback Terminal
LDO Output
Power in from either DC source or battery to LDO2.
Connection isn't necessary for electrical performance, but it is
recommended for better thermal dissipation.
VIN+
VIN+
I: Input Pin
4
I/O: Input/Output Pin
Note
Always Powered
Always Powered
If Enabled, Min VIN is 1.74V
If Enabled, Min VIN is 1.74V
Description
O: Output Pin
2
C, Logic)