CS

+

-

CSG

CS AMPLIFIER

+

+

-

FB

COMP

SS

GM ERROR

AMPLIFIER

VISNS

VOSNS

SLOPE

SLOPE COMP

BUCK-BOOST CONTROLLER

LOGIC

RT/SYNC

DITH

OSC/SYNC

CLK

ILIMIT

COMPARATOR

PWM

COMPARATOR

VCC

VCC

BOOT1

HDRV1

SW1

LDRV1

BOOT2

HDRV2

SW2

LDRV2

HICCUP CURRENT

LIMIT

MODE

AGND

PGND

EN/UVLO

+

-

ISNS(+)

ISNS(-)

45 mV

+

-

SS

CONSTANT

CURRENT LOOP

VIN

VCC

EN & BIAS

LOGIC

THERMAL

SHUTDOWN

CLK

BIAS

+

-

+

-

+

-

+

-

+

-

+

-

FB

PGOOD

OV

1.2 V

1 mA/V

+

-

OPERATING

STANDBY

1.6V

3.3V

13

LM5176

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SNVSAI1A – JUNE 2017 – REVISED MARCH 2019

Product Folder Links: LM5176

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7.2 Functional Block Diagram

7.3 Feature Description

7.3.1 Fixed Frequency Valley/Peak Current Mode Control with Slope Compensation

The LM5176 implements a fixed frequency current mode control of both the buck and boost switches. The output

voltage, scaled down by the feedback resistor divider, appears at the FB pin and is compared to the internal

the current sense signal measured across the CS and CSG pins. The result is compared to the COMP error

voltage by the PWM comparator.