TDA4605 STMicroelectronics, TDA4605 Datasheet - Page 5

• Manufacturer Part Number: TDA4605
• Description: IC POWER SUPPLY CONTROLLER 8DIP
• Manufacturer: STMicroelectronics

Specifications of TDA4605

• Applications: Power Supply Controller
• Operating Temperature: -20°C ~ 85°C
• Mounting Type: Through Hole
• Package / Case: 8-DIP (0.300", 7.62mm)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Supply: -
• Voltage - Supply: -
• Voltage - Input: -
• Other names: Q1660517

FUNCTIONAL DESCRIPTION
In free running fly-back converters, the TDA4605
assumes control of a MOS power transistor and all
necessary regulation and monitoring functions.
The serial circuit of power transistor and primary
winding of the flyback transformer is connected to
the input voltage. During the switch-on period of
the transistor, energy is stored in the transformer
and during the switch-off period it is fed to the load
via the secondary winding. By varying the switch-
on time of the power transistor, the IC controls
each portion of energy transferred to the second-
ary side such that the output voltage remains near-
ly independent of load variations.
The required control information is taken from the
input voltage during the switch-on period and from
a regulation winding during the switch-off period. A
new cycle begins as soon as the energy stored in
the transformer has been totally delivered to the
secondary side.
In different load ranges, the SMPS will behave as
follows:
– No-Load Operation: The power supply unit os-
– Normal Operation: Starting from typ. 200kHz,
– Overload Point: Maximum output power is
– Overload: The energy transferred per operation
cillates in non continuous mode at a typical fre-
quency of 20 to 40kHz. Depending upon the
transformer winding and the regulated voltage di-
vider, the output voltage can be slightly above
the nominal value.
the switching frequency falls with increasing load
and decreasing AC voltage. The duty cycle de-
pends primarily on the AC voltage. The output
voltage is only slightly load-dependent.
available at this point of the output characteris-
tics
cycle is limited at the top. Therefore, the output
voltage will fall with secondary overloading.
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