Infineon TDA 16846, TDA 16846-2, TDA 16847, TDA 16847-2 Service Manual

Data Sheet, Version1.3, July 2003

TDA 16846 TDA 16846-2 TDA 16847 TDA 16847-2

Controller for Switch Mode Power Supplies Supporting Low Power Standby and Power Factor

Power Management & Supply

Never stop thinking.

TDA 16846/TDA 16846-2 Revision History: Current Version: 2003-07-31

Previous Version Data Sheet TDA 16846: 2000-01-14 Previous Version Data Sheet TDA 16846-2: 2002-07-30

Page (in previous Version) 20

Page (in current Version) 20

Subjects (major changes since last revision) The data sheets for TDA 16846 and TDA 16846-2 have been combined in this version. Some measuring values are updated:

Pin 1 basic value 1

1B1

Pin 2 discharge current Pin 14 overvoltage

14OVmax

Pin 3 delay to switch on

1min

4ch

Pin 4 charge current Pull high resistor

and V

2DC min

slightly decreased.

and discharge current I

changed from 18kOhm to 15 kOhm acc ording

slightly changed.

1B2

changed from 0.5 mA to 0.6 mA.

threshold changed from 17.0 V to 17.1 V.

added.

4DCH

to the data sheet for TDA 16846. 22 23

22 23

Pin 7 charge current

and upper threshold V

7 min

Pin 13 rise and fall time a dapted acco rding to

13aclow

slightly decreased (only TDA 16846-2, TDA 16847-2).

small changed.

7Hmin

= 1nF (prev. 10 nF).

TDA 16846-2/TDA 16847-2: Improvements of TDA 16846-2/TDA16847-2 compared with TDA 16846/TDA16847

Pin 5 OCI Expanded input voltage range down to zero, series resistor between

pin 5 and ground is no longer necessary. Pin 7 SYN Improved startup to prevent the transformer from saturation also in

fixed frequency and synchronized mode. Pin 11 PVC Noise-immunity improved by spike blanking. Pin 13 OUT Reduced output voltage level for off state. Pin 14 VCC Noise-immunity improved by spike blanking.

Edition 07.03

Published by Infineon Technologies AG St.-Martin-Strasse 53 D-81541 München

Attention please!

The information herein is given to describe certain components and shall not be considered as warranted characteristics.

Terms of delivery and rights to technical change reserved.

We hereby disclaim any and all warranties, including but not limited to warranties of non-infringement, regarding circuits, descriptions and charts stated herein.

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Information

For further information on technology, delivery terms and conditions and prices please contact your nearest Infineon Technologies Office in Germany or our Infineon Technologies Representatives worldwide.

Warnings

Due to technical requirements components may contain dangerous substances. For information on the types in question please contact your nearest Infineon Technologies Office.

Infineon Technologies Components may only be used in life-support devices or systems with the express written approval of Infineon Technologies, if a failure of such components can reasonably be expected to cause the failure of that life-support device or system, or to affect the safety or effectiveness of that device or system. Life support devices or systems are intended to be implanted in the human body, or to support and/or maintain and sustain and/or protect human life. If they fail, it is reasonable to assume that the health of the user or other persons may be endangered.

Controller for Switch Mode Power Supplies Supporting Low Power Standby and Power Factor Correction

1Overview

1.1 Features

• Line Current Consumption with PFC

• Low Power Consumption

• Stable and Adjustable Standby Frequency

• Very Low Start-up Current

• Soft-Start for Quiet Start-up

• Free usable Fault Comparators

• Synchronization and Fixed Frequen cy Ci rcuits

• Over- and Undervoltage Lockout

• Switch Off at Mains Undervoltage

• Temporary High Power Circuit (only TDA 16847-2)

• Mains Voltage Dependent Fold Back Point Correction

• Continuous Frequency Reduction with Decreasing Load

• Adjustable and Voltage Dependent Ringing Suppression Time

P-DIP-14-3

P-DSO-14-3

TDA 16846

TDA 16846-2

Bipolar IC

Type Ordering Code Package

TDA 16846 Q67000-A9377 P-DIP-14-3 TDA 16847 Q67000-A9378 P-DIP-14-3 TDA 16846G Q67006-A9430 P-DSO-14-3 TDA 16847G Q67006-A9412 P-DSO-14-3 TDA 16846-2 Q67040-S4494 P-DIP-14-3 TDA 16847-2 Q67040-S4496 P-DIP-14-3 TDA 16846-2G Q67040-S4495 P-DSO-14-3 TDA 16847-2G Q67040-S4497 P-DSO-14-3

1.2 Description

The TDA 16846-2 (this name is used in the description for all types) is optimized to control free running or fixed f requency flyback con verters with or witho ut Power Factor Correction (Current Pump). To provide low power consumption at light loads, this device reduces the switching frequency in small steps with load, towards an adjustable minimum (e. g. 20 kHz in standby mode). Additionally, the startup current is very low. To avoid switching stress on the power devices, the power transistor is always switched on at minimum voltage. A special circuit is implemented to avoid jitter. The device has

Data Sheet 3 2003-07-31

TDA 16846

TDA 16846-2

several protection function s: VCC over- and undervoltage, ma ins undervoltage, current limiting and 2 free usable fault comparators. Regulation can be done by using the internal error amplifier or an opto co upler feedbac k (additional in put). The output driv er is ideally suited for driving a power MOSFET. Fixed frequency and synchronized operation are also possible.

The TDA 16846-2 is suited for TV-, VCR- sets, SAT receivers and other sets for consumer electronics. It also can be used in PC monitors.

The TDA 16847-2 is identical with TDA 16846-2 but has an additional power measurement output (pin 8) which can be used as a Temporary High Power Circuit.

Figure 1 Pin Configuration (top view)

1.3 Pin Definitions and Functions

Pin Symbol Function

1 OTC Off Time Circuit 2 PCS Primary Current Simulation 3 RZI Regulation and Zero Crossing Input 4 SRC Soft-Start and Regulation Capacitor 5 OCI Opto Coupler Input 6 FC2 Fault Comparator 2 7 SYN Synchronization Input 8 N.C./PMO Not Connected (TDA 16846-2) / PMO (TDA 16847-2) 9 REF Reference Voltage and Current 10 FC1 Fault Comparator 1 11 PVC Primary Voltage Check 12 GND Ground 13 OUT Output 14 VCC Supply Voltage

Data Sheet 4 2003-07-31

TDA 16846

TDA 16846-2

1.4 Short Description of the Pin Functions

Pin Function

1 A parallel RC-circuit between this pin and ground determines the ringing

suppression time and the standby-frequency.

2 A capacitor between this pin and ground and a resistor between this pin and

the positive terminal of the primary electrolytic capacitor quantifies the max. possible output power of the SMPS.

3 This is the input of the error amplifier and the zero crossing input. The output

of a voltage divider between the control winding and ground is connected to this input. If the pulses at pin 3 exceed a 5 V threshold, the control voltage at pin 4 is lowered.

4 This is the pin for the control voltage. A capacitor has to be connected

between this pin and ground. The value of this capacitor determines the duration of the softstart and the speed of the control (primary regulation).

5 If an opto coupler for the control is used, its output has to be connected

between this pin and ground. The voltage divider at pin 3 has then to be

changed, so that the pulses at pin 3 are below 5 V. 6 Fault comparator 2: A voltage > 1.2 V at this pin stops the SMPS (v.also pin 9). 7 If fixed frequency mode is wanted, a parallel RC circuit has to be connected

between this pin and ground. The RC-value determines the frequency. If

synchronized mode is wanted, sync pulses have to be fed into this pin. 8 TDA 16846-2: Not connected. TDA 16847-2: This is the power measurement

output of the Temporary High Power Circuit. A capacitor and a RC-circuit has

to be connected between this pin and ground. 9 Output for the reference voltage (5 V). With a resistor between this pin and

ground the fault comparator 2 (pin 6) is enabled. 10 Fault comparator 1: If a voltage > 1 V is applied to this pin, the SMPS stops. 11 This is the input of the primary voltage check. The voltage at the anode of the

primary electrolytic capacitor has to be fed to this pin via a voltage divider. If

the voltage of this pin falls below 1 V, the SMPS is switched off. A second

function of this pin is the primary voltage dependent fold back point correction

(only active in free running mode). 12 Common ground. 13 Output signal. This pin has to be connected via a series resistor to the gate of

the power transistor. 14 Connection for supply voltage and startup capacitor. After startup, the supply

voltage is produced by the control winding of the transformer and rectified by

an external diode.

Data Sheet 5 2003-07-31

1.5 Block Diagrams

TDA 16846

TDA 16846-2

Figure 2 TDA 16846-2

Data Sheet 6 2003-07-31

TDA 16846

TDA 16846-2

Figure 3 TDA 16847-2

Data Sheet 7 2003-07-31

TDA 16846

TDA 16846-2

2 Functional Description

Start Up Behaviour (Pin 14)

When power is applied to the chip and the vol tage

upper threshold (

will be less than 100 µA. The chip is not active (off state) and driver output (Pin 13)

) of the Supply Voltage Comparator (SVC), the n the input current

and control output (Pin 4) will be active ly held low. When threshold ( SVC threshold ( start-up circuit and Figure 5 shows the vo ltage done by resistor

) the chip starts working and I14 increases. When V14 falls below the lower

) the chip starts again from its initi al condi tion. Figure 4 shows t he

OFF

of the “Primary Current Simulation” (see later) and the internal diode

D1, so no additional start up resistor is needed. The capacito r current until the auxiliary winding of the transformer supplies the chip with current through the external diode D14.

at Pin 14 (VCC) is less than the

exceeds the upper SVC

during start up. Chargi ng of C14 is

delivers the supply

It is recommended to apply a small RF snubber cap acitor of e.g. 100 nF parallel to t he electrolytic capacitor at pin 14 as shown in the application circuits in Figures 15, 16 , and

17. To avoid multiple pulses during start up in fixed frequency mode (danger of transformer

saturation), the IC works in freerunni ng mode un til th e pulses at pin 3 (RZ I) exceed the

2.5 V threshold (only TDA 16846-2, TDA 16847-2).

Figure 4 Startup Circuit

Data Sheet 8 2003-07-31

TDA 16846

TDA 16846-2

Figure 5 Startup Voltage Diagram

Primary Current Simulation PCS (Pin 2) / Current Limiting

A voltage proportional to the current of the power transistor is generated at Pin 2 by the RC-combination power transistor is switched off an d during its switch on time the rectified mains. The equation of

: Primary inductance of the transformer

primary

The voltage The other input is the control voltage. If

, C2 (Figure 4). The voltage at Pin 2 is forced to 1.5 V when the

is charged by R2 from

and the current in the power transistor (I

is applied to one input of the On Time Comparator ONTC (see Figure 2).

1,5 V

primaryIprimary

--------------------------------+=

R2C

exceeds the control voltage, the driver

primary

) is

switches off (current limiting ). The maximum valu e of the control vol tage is the internal reference voltage 5 V, so the maximum current in the power transistor (

Mprimary

) is

Mprimary

--------------------------------------=

primary

The control voltage can be reduced by either the Error Amplifier EA (current mode regulation), or by an opto co upler at Pin 5 (regulation with opto coup ler isolation) or by

3,5 V R2× C2×

the voltage

Data Sheet 9 2003-07-31

at Pin 11 (Fold Back Point Correction).

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