MP9928—4V TO 60V SYNCHRONOUS STEP-DOWN CONTROLLER

MP9928 Rev. 1.0

www.MonolithicPower.com

13

5/20/2016

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PIN FUNCTIONS

TSSOP

Pin #

QFN

Pin #

Name

Description

1

19

IN

Input supply. The MP9928 operates from a 4V to 60V input. Ceramic

capacitor is needed to prevent large voltage spikes from appearing at the

input.

2

20

EN/SYNC

Enable input. The threshold is 1.22V with 130mV of hysteresis, and it is

used to implement an input under voltage lockout (UVLO) function

externally. If an external sync clock is applied to this pin, internal clock will

follow the sync frequency.

3

1

VCC2

External power supply for the internal VCC1 regulator. It will disable the

power supply to this pin. Connecting VCC2 pin to external power supply

will reduce power dissipation and thus increases efficiency.

4

2

VCC1

Internal bias supply. Decouple with a 1µF ceramic capacitor or greater

ceramic capacitor. But the capacitance should be no more than 4.7µF.

5

3

SGND

Low noise signal ground reference.

6

4

SS

Soft-start control input. This pin is used to program the soft-start period

with an external capacitor between SS to SGND.

7

5

COMP

COMP is used to compensate the regulation control loop. Connect an RC

network from COMP to GND to compensate for the regulation control loop.

8

6

FB

Feedback. This is the input to the error amplifier. An external resistive

divider connected between the output and GND is compared to the internal

+0.8V reference to set the regulation voltage.

9

7

CCM/AAM

Continuous conduction mode/advanced asynchronous mode set pin.

Connect this pin to VCC1 pin or float can set the part operates in CCM

mode. Connecting an appropriate external resistor from this pin to GND to

make AAM at low level, can set the part operates in AAM. The AAM

voltage should be no less than 480mV.

10

8

FREQ

Connect a resistor between FREQ and GND to set the switching

frequency.

11

9

PG

Power good output. The output of this pin is open drain.

12

10

ILIM

Current sense voltage limit set. The voltage at this pin sets the nominal

sense voltage at maximum output current. There are three fixed options

(float, connect to VCC1 or connect to GND.)

13

11

SYNCO

outputs a clock which are 180° out-of-phase with internal Oscillator Clock

or external Synchronize Clock when part works in CCM or DCM(but not

Sleep mode) for dual channel co-pack. SYNCO outputs DC voltage in

other cases(Sleep mode, Low Dropout mode, Fault protections, etc.).

14

12

SENSE-

Negative input for the current sense. The sensed inductor current limit

threshold is determined by status of ILIM pin.

15

13

SENSE+

Positive input for the current sense. The sensed inductor current limit

threshold is determined by status of ILIM pin.

16

14

PGND

Power ground reference for the internal low side switch driver and the

VCC1 regulator circuit. Connect this pin directly to the negative terminal of

the VCC1 decoupling capacitor.