TDA4605-2 Infineon Technologies, TDA4605-2 Datasheet - Page 9

• Manufacturer Part Number: TDA4605-2
• Description: IC POWER SUPPLY CONTROLLER 8DIP
• Manufacturer: Infineon Technologies

Specifications of TDA4605-2

• Applications: Power Supply Controller
• Voltage - Supply: 7.5 V ~ 15.5 V
• Current - Supply: 11mA
• Operating Temperature: -20°C ~ 85°C
• Mounting Type: Through Hole
• Package / Case: 8-DIP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Input: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: SP000011728; TDA46052X; TDA46052XK

Pin 7
By means of a resistor pin 7 is connected with the output of the control amplifier. If
equal to the control voltage
characteristics. The response of the control loop is derived from the capacitor connected to pin 7. If
V
capacitor connected to pin 7.
Pin 8
The zero crossing detector controlling the logic block recognizes the complete discharge of the
energy stored in the transformator core by detecting the zero crossing the positive to negative
voltage transition of the voltage at pin 8. This enables the logic for a new pulse. Parasitic oscillations
occurring at the end of a pulse cannot lead to a new pulse because of an internal circuit which
inhibits the zero detector for a certain dead time
Start-Up Behaviour
The start-up behaviour of the application circuit (which is given on page 68) is explained in the
diagrams on page 70 for a line voltage barely above the lower acceptable lower limit of the mains
voltage. After applying the mains voltage at the time
be seen:
The current drawn by the IC in this case is less than 0.8 mA.
If
switched on. The supply current drawn by the IC rises to 12 mA max.. The primary current/voltage
converter reduces
point
pulses including the start pulse are controlled by means of the control and overload amplifier. After
turn on the IC is generating a signal at pin 7 which slowly ramping up. This signal is used to increase
the duration of the output pulses slowly (soft-start function). The max. output pulse width is limited
by means of the overload amplifier. If the feedback control voltage
amplifier allows the generation of output pulses with a wider pulse width. The max. pulse width is
reached at time
Thereafter the peak values of
is in a steady, operational state.
If the voltage
attempt to start the SMPS is aborted (pin 5 is switched to low). As the internal circuits of the IC
remain switched on,
the diagram) and new start-up attempt begins at time
Version 2.0
1
V
–
–
–
is equal to 0 V the control and overload amplifier is generating a ramp-up function using the
6
t
V
V
V
reaches the threshold (at the time t
5
6
2
3
to
corresponding to the half-wave charge current over
to
to the value determined by the divider
t
6
V
in the diagram. The feedback to pin 8 starts the next pulse and so on. The width of all
2 max
V
6
falls below the switch-off threshold
t
2
(typically 6.6 V)
V
in the diagram (
2
V
down to
6
further decreases to
V
V
2
2B
V
decrease rapidly, because of the IC control range. The control loop
R
and the start pulse generator generates the start pulses from time
V
the control amplifier has a proportional integrating control
2
=
V
2S max
1
in the diagram), the IC internal reference voltage is
V
9
6A
R
). The IC is then operating at the fold-back point.
t
10
. The IC switches off;
UL
/
t
R
V
after the end of each pulse.
0
11
6 min
the following built up of different voltages can
t
1
.
before the foldback point is reached, the
R
1
V
1
V
is increasing, the overload
6
can rise again (time
TDA 4605-2
V
1
is approx.
1 Jul 2002
t
4
in