TDA4865J Datasheet, PDF (4/18 Pages) NXP Semiconductors – eflection boosters for use in vertical deflection systems for frame frequencies up to 200 Hz.

NXP Semiconductors
TDA4865J; TDA4865AJ
Vertical deflection booster
6.2 Pin description
Table 3.
Symbol
V_P1
V_FB
V_P3
V_P2
GND
VOUT
INN
INP
Pin description
Pin
TDA4865J TDA4865AJ
1
1
2
-
-
2
3
3
4
4
5
5
6
6
7
7
Description
positive supply voltage 1
flyback supply voltage
flyback generator output
supply voltage 2 for vertical output
ground or negative supply voltage
vertical output
inverted input of differential input stage
non-inverted input of differential input stage
7. Functional description
Both the TDA4865J and TDA4865AJ consist of a differential input stage, a vertical output
stage, a flyback generator, a reference circuit and a thermal protection circuit.
The TDA4865J operates with a separate flyback supply voltage (see Figure 1) while the
TDA4865AJ generates the flyback voltage internally by doubling the supply voltage
(see Figure 2).
7.1 Differential input stage
The differential sawtooth input current signal (from the deflection controller) is connected
to the inputs (inverted signal to pin INN and non-inverted signal to pin INP). The vertical
feedback signal is superimposed on the inverted signal on pin INN.
7.2 Vertical output and thermal protection
The vertical output stage is a quasi-complementary class-B amplifier with a high linearity.
The output stage is protected against thermal overshoots. For a junction temperature of
T_j > 150 °C the protection will be activated and will reduce the deflection current (I_VOUT).
7.3 Flyback generator
The flyback generator supplies the vertical output stage during flyback.
The TDA4865J is used with a separate flyback supply voltage to achieve a short flyback
time with minimized power dissipation.
The TDA4865AJ needs a capacitor (C_F) connected between pins V_P3 and V_P2 (see
Figure 2). Capacitor C_F is charged during scan, using the external diode D1 and resistor
R5. During flyback the cathode of capacitor C_F is connected to the positive supply voltage
and the flyback voltage is then twice the supply voltage. For the TDA4865AJ the
resistor R6 in the positive supply line can be used to reduce the power consumption.
TDA4865J_TDA4865AJ_2
Product data sheet
Rev. 02 — 3 November 2006
© NXP B.V. 2006. All rights reserved.
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