lm5039mhx National Semiconductor Corporation, lm5039mhx Datasheet - Page 4

• Manufacturer Part Number: lm5039mhx
• Description: Half-bridge Pwm Controller With Average Current Limit
• Manufacturer: National Semiconductor Corporation

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TSSOP
Pin
EP
10
11
12
13
14
15
16
17
18
19
20
9
LLP Pin
EP
11
12
13
14
15
16
17
18
19
21
10
20
22
8
9
1
PGND
Name
RES
VCC
DLY
SR2
SR1
REF
VIN
HO
HB
HS
NC
NC
NC
NC
LO
EP
Timing programming pin for the
LO and HO to SR1 and SR2
outputs.
Restart Timer
Boost voltage for the HO driver
Switch node
High side gate drive output.
Low side gate drive output.
Power Ground
Output of the high voltage start-up
regulator. The VCC voltage is
regulated to 7.6V.
Synchronous rectifier driver
output.
Synchronous rectifier driver
output.
Output of 5V Reference
Input voltage source
Exposed Pad, underside of
package
No connection
No connection
No connection
No connection
Description
4
An external resistor to ground sets the timing for the non-overlap
time of HO to SR1 and LO to SR2.
If the current limit is exceeded during any cycle, a 22µA current
is sourced to the RES pin capacitor. If the RES capacitor voltage
reaches 2.5V, the soft-start capacitor will be fully discharged and
then released with a pull-up current of 1.2µA. After the first output
pulse at LO (when SS > COMP offset, typically 1V), the SS pin
charging current will revert to 110µA.
An external diode is required from VCC to HB and an external
capacitor is required from HS to HB to power the HO gate driver.
Connection common to the transformer and both power switches.
Provides a return path for the HO gate driver.
Output of the high side PWM gate driver. Capable of sinking 2A
peak current.
Output of the low side PWM gate driver. Capable of sinking 2A
peak current.
Connect directly to Analog Ground.
If an auxiliary winding raises the voltage on this pin above the
regulation setpoint, the Start-up Regulator will shutdown, thus
reducing the internal power dissipation.
Control output of the synchronous FET gate. Capable of 0.5A
peak current.
Control output of the synchronous FET gate. Capable of 0.5A
peak current.
Typical output current is 20mA. Locally decoupled with a 0.1µF
capacitor.
Input to the Start-up Regulator. Operating input range is 13V to
100V with transient capability to 105V. For power sources outside
of this range, the LM5039 can be biased directly at VCC by an
external regulator.
No electrical contact. Connect to system ground plane for
reduced thermal resistance.
No electrical contact.
No electrical contact.
No electrical contact.
No electrical contact.
Application Information