lm25088mhx-2 National Semiconductor Corporation, lm25088mhx-2 Datasheet - Page 2

• Manufacturer Part Number: lm25088mhx-2
• Description: Wide Input Range Non-synchronous Buck Controller
• Manufacturer: National Semiconductor Corporation

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Pin(S)
Connection Diagrams
Ordering Information
Pin Descriptions
1
2
3
4
LM25088MHX-1
LM25088MHX-2
Order Number
LM25088MH-1
LM25088MH-2
RAMP
Name
VIN
EN
SS
Top View (Dither version)
LM25088-1
Input supply voltage
Ramp control signal
Description
Enable input
Soft-start
TSSOP-16EP, Dithering
TSSOP-16EP, Dithering
TSSOP-16EP, Restart
TSSOP-16EP, Restart
Description
30087602
Application Information
IC supply voltage. The operating range is 4.5V to 42V.
If the EN pin voltage is below 0.4V the regulator will be in a low power state. If
the EN pin voltage is between 0.4V and 1.2V the controller will be in standby
mode. If the EN pin voltage is above 1.2V the controller will be operational. An
external voltage divider can be used to set a line under voltage shutdown
threshold. If the EN pin is left open, a 5µA pull-up current forces the pin to the
high state and enables the controller.
When SS is below the internal 1.2V reference, the SS voltage will control the
error amplifier. An internal 11 µA current source charges an external capacitor
to set the start-up rate of the controller. The SS pin is held low in the standby,
VCC UV and thermal shutdown states. The SS pin can be used for voltage
tracking by connecting this pin to a master voltage supply less than 1.2V. The
applied voltage will act as the reference for the error amplifier.
An external capacitor connected between this pin and the GND pin sets the
ramp slope used for emulated current mode control. Recommended capacitor
range 100 pF to 2000 pF. See the Applications section for selection of capacitor
value.
2
NSC Package Drawing
MXA16A
MXA16A
MXA16A
MXA16A
Top View (Restart version)
LM25088-2
2500 Units on Tape and Reel
2500 Units on Tape and Reel
73 Units in a Rail
73 Units in a Rail
Supplied As
30087603