Monday, January 11, 2016

GRUNDIG Cinemo 40 LCD television Power supply circuit – L6598 – VIPer22 - LCD television repair and service

Category: LCD Television Repair and service 

Contents of this article 

  • L6598 Smps driver ic
  • VIPer22 
  • Power supply Schematic diagram 




GRUNDIG Cinemo 40

L6598 High voltage resonant controller
Description
The L6598 device is manufactured with the BCD offline technology, able to ensure voltage ratings up to 600 V, making it perfectly suited for AC/DC adapters and wherever a resonant topology can be beneficial. The device is intended to drive two power MOSFETs, in the classical half bridge topology. A dedicated timing section allows the designer to set soft-start time, soft-start and minimum frequency. An error amplifier, together with the two enable inputs, are made available. In addition, the integrated bootstrap diode and the Zener clamping on low voltage supply, reduces to a minimum the external parts needed in the applications.
# High voltage rail up to 600 V
# dV/dt immunity ±50 V/ns in full temperature range
# Driver current capability: 250 mA source 450 mA sink
# Switching times 80/40 ns rise/fall with 1 nF load
# CMOS shutdown input
# Undervoltage lockout
# Soft-start frequency shifting timing
PIN CONFIGARATION AND FUNCTION
Pin no.
Name
Function
1
CSS
Soft-start timing capacitor
2
R fstart
Soft-start frequency setting - low impedance voltage source -see also Cf
3
C f
Oscillator frequency setting - see also Rfmin, Rfstart
4
R fmin
Minimum oscillation frequency setting - low impedance voltage source - see also Cf
5
O Pout
Sense op amp output - low impedance
6
O Pon-
Sense op amp inverting input -high impedance
7
O Pon+
Sense op amp non inverting input - high impedance
8
EN1
Half bridge latched enable
9
EN2
Half bridge unlatched enable
10
GND
Ground
11
LVG
Low side driver output
12
V s
Supply voltage with internal Zener clamp
13
N.C.
Not connected
14
OUT
High side driver reference
15
HVG
High side driver output
16
V boot
Bootstrapped supply voltage

VIPer22A Low power OFF-line SMPS switcher
Description
The VIPer22A-E combines a dedicated current mode PWM controller with a high voltage power MOSFET on the same silicon chip.
Typical applications cover off line power supplies for battery charger adapters, standby power supplies for TV or monitors, auxiliary supplies for motor control, etc. The internal control circuit offers the following benefits: Large input voltage range on the VDD pin accommodates changes in auxiliary supply voltage. This feature is well adapted to battery charger adapter configurations. Automatic burst mode in low load condition. Overvoltage protection in HICCUP mode.
# Fixed 60 kHz switching frequency
# 9 V to 38 V wide range VDD voltage
# Current mode control
# Auxiliary undervoltage lockout with hysteresis
# High voltage start-up current source
# Overtemperature, overcurrent and overvoltage
# protection with auto-restart
PIN CONFIGRATION AND FUNCTION
Pin Name
Pin function
V DD







Power supply of the control circuits. Also provides a charging current during start up
thanks to a high voltage current source connected to the drain. For this purpose, an
hysteresis comparator monitors the VDD voltage and provides two thresholds:
- V DDon: Voltage value (typically 14.5 V) at which the device starts switching and turns
off the start up current source.
- V DDoff: Voltage value (typically 8 V) at which the device stops switching and turns on
the start up current source.

SOURCE

Power MOSFET source and circuit ground reference.


DRAIN

Power MOSFET drain. Also used by the internal high voltage current source during
start up phase for charging the external VDD capacitor.



FB
Feedback input. The useful voltage range extends from 0 V to 1 V, and defines the
peak drain MOSFET current. The current limitation, which corresponds to the
maximum drain current, is obtained for a FB pin shorted to the SOURCE pin.

 POWER SUPPLY SCHEMATIC DIAGRAM 
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