LM3661TL-1.25 NSC [National Semiconductor], LM3661TL-1.25 Datasheet - Page 3

• Manufacturer Part Number: LM3661TL-1.25
• Description: 450mA Subminiature, Micropower Step-Down DC-DC Converter for Ultra Low-Voltage Circuits
• Manufacturer: NSC [National Semiconductor]

Connection Diagrams
10-Bump micro SMD Package
Ordering Information
Pin Description
Pin Number
A1
B1
C1
D1
D2
D3
C3
B3
LM3661TLX - 1.25
LM3661TLX - 1.35
LM3661TL - 1.35
LM3661TLX - 1.40
LM3661TL - 1.40
LM3661TL - 1.25
Order Number
FB
V
I
SYNC/MODE
EN
PGND
SW
PV
SEL
SEL
IN
Name
Output Voltage
1.05V/1.25V
1.05V/1.35V
1.05V/1.40V
Top View
Feedback Analog Input. Connect to the output at the output filter capacitor (see
Typical Application Circuit)
Output Voltage Selection Input. Set this digital input to select the desired output
voltage. Set:
I
I
Synchronization Input. Use this digital input for frequency selection or modulation
control. Set:
external clock in PWM mode.
The LM3661 synchronizes with the rising edge of the external clock.
Enable Input. It has an internal pull down resistor of 1 Mohms. Set this digital input
high for normal operation. For shutdown, set low.
Power Ground
Switching Node connection to the internal PFET switch and NFET synchronous
rectifier. Connect to an inductor with a saturation current rating that exceeds the peak
current limit.
Power Supply Input to the internal PFET switch. Connect to the input filter capacitor
(See Typical Application Circuit).
• V
• V
• SYNC/MODE = high for low-noise 600 kHz PWM mode
• SYNC/MODE = low for micropower linear mode
• SYNC/MODE = a 500 kHz -750 kHz external oscillator for synchronization to an
SEL
SEL
SEL
SEL
10Bump Wafer Level
Chip Scale (micro SMD)
= High (
= Low (GND) for set current limit to high value
= high programmed ouput voltage
= low for low programmed output voltage
20098804
Package
>
1.2V) for set current limit to low value
3
NSC Package Marking
Function
SHVB
SHVB
SDYB
SDYB
SHCB
SHCB
Bottom View
3000 Units, Tape and Reel
250 Units, Tape and Reel
3000 Units, Tape and Reel
250 Units, Tape and Reel
3000 Units, Tape and Reel
250 Units, Tape and Reel
Supplied As
20098805
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