lm2618 National Semiconductor Corporation, lm2618 Datasheet - Page 3

• Manufacturer Part Number: lm2618
• Description: 400ma Sub-miniature, High Efficiency, Synchronous Pwm & Pfm Programmable Dc-dc Converter
• Manufacturer: National Semiconductor Corporation

Pin Description
Pin Number (*)
(*) Note that the pin numbering scheme for the microSMD package was revised in April,2002 to conform to JEDEC standard. Only the pin numbers were revised.
No changes to the physical location of the inputs/outputs were made. For reference purpose, the obsolete numbering had FB as pin 1, VID1 as pin 2, VID0 as pin
3, SYNC as pin 4, EN as pin 5, PGND as pin 6, SW as pin 7, PVIN as pin 8, VDD as pin 9 and SGND as pin 10.
A1
B1
C1
D1
D2
D3
C3
B3
A3
A2
SYNC/MODE
Pin Name
PGND
SGND
PVIN
VID1
VID0
VDD
SW
EN
FB
Feedback Analog Input. Connect to the output at the output filter capacitor (Figure 1)
Output Voltage Control Inputs. Set the output voltage using these digital inputs (see Table
1). The output defaults to 1.87V if these pins are unconnected.
Synchronization Input. Use this digital input for frequency selection or modulation control.
Set:
SYNC/MODE = high for low-noise 600kHz PWM mode
SYNC/MODE = low for low-current PFM mode
SYNC/MODE = a 500kHz - 1MHz external clock for synchronization to an external clock
in PWM mode. See Synchronization and Operating Modes in the Device Information
section.
Enable Input. For shutdown, set low to SGND. (See Shut down Mode in the Device
Information section.)
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 max Switch Peak
Current Limit specification of the LM2618 (Figure 1)
Power Supply Input to the internal PFET switch. Connect to the input filter capacitor
(Figure 1).
Analog Supply Input. If board layout is not optimum, an optional 0.1µF ceramic capacitor
is suggested (Figure 1)
Analog and Control Ground
3
Function
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