TU-X1E (serv.man8). Major IC Informations - Sharp TV Service Manual (repair manual). Page 13

TU-X1E/RU

7 – 13

1

BOOT

I

HS Driver Supply.
Connect through a capacitor (100nF) to the floating node (LS-Drain) pin
and provide necessary bootstrap diode from VCC.

2

UGATE

-

HS Driver Output. Connect to HS mosfet gate.

3

GND

I

All internal references, logic and drivers are connected to this pin.
Connect to the PCB ground plane.

4

LGATE/OC

I

LGATE. LS Driver Output. Connect to LS mosfet gate.
OC. Over Current threshold set. During a short period of time following
VCC rising over UVLO threshold, a 10

µA current is sourced from this pin.

Connect to GND with an ROCSET resistor greater than 5k

Ω to program OC 

Threshold. The resulting voltage at this pin is sampled and held internally as the 
OC set point. Maximum programmable OC threshold is 0.55V. 
A voltage greater than 0.75V (max) activates an internal clamp and causes
OC threshold to be set at 400 mV. 
ROCSET not connected sets the 400mV default threshold.

5

VCC

-

Device and LS Driver power supply.
Operative range from 4.1V to 13.2V. Filter with at least 1

µF MLCC to GND.

6

FB

I

Error Amplifier Inverting Input.
Connect with a resistor RFB to the output regulated voltage. Additional
resistor ROS to GND may be used to regulate voltages higher than the reference.

7

COMP/DIS

 

I

COMP. Error Amplifier Output. Connect with an RF - CF // CP to GND to
compensate the device control loop in conjunction to the FB pin.
During the Soft-Start phase, a 10

µA current is sourced from this pin so the

compensation capacitors also act to program the SS time.
DIS. The device can be disabled by pulling this pin lower than 0.4V (min).
Setting free the pin, the device enables again.

8

PHASE

I

HS Driver return path, current-reading and adaptive-dead-time monitor.   
Connect to the LS drain to sense RdsON drop to measure the output current.  
This pin is also used by the adaptive-dead-time control circuitry to monitor   
when HS mosfet is OFF.   

1

BS

I

High-Side gate drive boost input. BS supplies the drive for the high-side N-Channel 
MOSFET switch. Connect a 0.01

µF or greater capacitor from SW to BS to power the 

high-side switch.

2

IN

 

-

Power input. IN supplies the power to the IC, as well as the step-down converter 
switches. Drive IN with a 4.75V to 28V power source. Bypass IN to GND with a suit-
ably large capacitor to eliminate noise on the input to the IC. 

3

SW

O

Power switching output. SW is the switching node that supplies power to the output. 
Connect the output LC filter from SW to the output load. Note that a capacitor is 
required from SW to BS to power the high-side switch.

4

GND

 -

Ground

5

FB

I

Feedback input. FB senses the output voltage to regulate that voltage. Drive FB with a 
resistive voltage driver from the output voltage. The feedback reference voltage is 
0.795V. 

6

FB

I

Compensation Node. COMP is used to compensate the regulation control loop. Con-
nect a series RC network from COMP to GND to compensate the regulation control 
loop. In side cases, an additional capacitor from COMP to GND is required.

7

EN

I

Enable Input. EN is a digital input that turns the regulator on or off. Drive EN higher 
than 2.7V to turn on the regulator, drive it lower than 1.1V to turn it off . Pull up with 
100K resister for automatic startup.

8

SS

I

Soft-start control input. SS control the soft-start period. Connect a capacitor from SS 
to GND to set the soft-start period.