Infineon TDA16847G, TDA16847, TDA16846G, TDA16846 Datasheet

ICs for Consumer Electronics

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

TDA 16846/TDA 16847

Data Sheet 2000-01-14

TDA 16846/TDA 16847 Revision History: Current Version: 2000-01-14

Previous Version: 1999-07-05 Page

(in previous Version)

Page (in current Version)

Subjects (major changes since last revision)

3 3, 28 P-DSO package added

Edition 01.00

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

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charts stated herein. Infineon Technologiesis an appro v ed CECC manufacturer.

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

TDA 16846

TDA 16847

Factor Correction

Preliminary Data Bipolar IC

1 Overview

1.1 Features

• Line Current Consumption with PFC

• Low Power Consumption

• Stable and Adjustable Standby Frequency

• Very Low Start-up Current

• Soft- Sta rt for Quiet Start-up

• Free usable Fault Comparators

• Synchronization and Fixed Frequency Facility

• Over- and Undervoltage Lockout

• Switch Off at Mains Undervoltage

• Temporary high power circuit (only TDA 16847)

• Mains Voltage Dependent Fold Back Point Correction

• Continuous Frequency Reduction with Decreasing Load

• Adjustable and Voltage Dependent Ringing Suppressi on Time

P-DIP-14-3

P-DSO-14-3

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

1.2 Description

The TDA 16846 is optimized to control free running or fixed frequency flyback converters with or without Power Factor Correction (Current Pump). To provide low power consumption at light loads, this device reduces the switching frequency continuously with load, towards an adj ust able mini mu m (e. g. 20 kHz i n sta ndby m ode) . Addition ally, the start up current is ve ry low. To avoid switching stresses of the power devices, the power transistor is always switched on at minimum voltage. A special circuit is

implemented to avo id jitter. The device has sev eral protec tion functions: undervoltage, main s under volta ge, c urrent limit ing and 2 f ree u sabl e fa ult com par ato rs. Regulation can be done by using the internal error amplifier or an opto coupler feedback (additional input). The output driver is ideally suited for driving a power MOSFET, but it can also be used for a bipolar transi stor. Fixed frequency and synchronized op eration are also possible.

over- a nd

Data Sheet 3 2000-01-14

TDA 16846

TDA 16847

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

The TDA 16847 is i denti cal with TDA 16846 but has an additional power measurement output (pin 8) which can be used for a Temporary High Power Circuit.

OTC

PCS

RZI

SRC

OCI

FC2

SYN N.C./PMO

1 2 3 4 5 6 7

Figure 1 Pin Configuration (top view)

1.3 Pin Definitions and Functions

Pin Symbol Function

1 OTC Off Time Circuit

14 13 12 11 10

9 8

AEP02647

VCC OUT GND PVC FC1 REF

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

Data Sheet 4 2000-01-14

TDA 16846 TDA 16847

1.4 Short Descri p tio n of the P in Fu nction s

Pin Function

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

suppression time and the standby-frequ ency.

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

the positive terminal of the primary elcap 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 connect ed 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.

5 If an opto coupler for the control is used, it’s 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: If a voltage > 1.2 V is applied to this pin, the SMPS stops. 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 freque ncy. If

synchronized mode is wanted, sync pulses have to be fed into this pin. 8 Not connected (TDA 16846). / 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 (TDA 16847). 9 Output for 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 elcap 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 across a serial resist or with 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 2000-01-14

1.5 Block Diagrams

SYN

OTC

RZI

SRC

OCI

5 V

4 5

3.5 V

30 k

Ω

75 k

Ω

Control Voltage

Limit

2 V

CS1

5 V

Off Time

Comparator

Error

Amplifier

Buffer for

Control Voltage

KSY

15 k

Ω

RSTC/RSTF

+ +

TDA 16846

TDA 16847

PVC

Primary Voltage

Check

FC2

1.2 V

9 8 6

REF N.C. FC2

Fold Back Point Correction

x 1/3

PVA

1 V

1.5 V

3.5 V

ED2

Error-

Flipflop

On Time

Flipflop

Output

Driver

OUT

PCS

20 k

Ω

5 V

On Time

Comparator

ED1

Zero Crossing Signal

15/8 V

Supply

Voltage

Comparator

1 V

FC1

AEB02648

GND

1.5 V D1 Startup Diode

< 25 mV

Overvoltage Comparator

14 12

The input with the lower voltage becomes operative

16 V

Figure 2 TDA 16846

Data Sheet 6 2000-01-14

SYN

OTC

RZI

SRC

OCI

5 V

3.5 V

4 5

30 k

Ω

75 k

Ω

Control Voltage

Limit

2 V

CS1

5 V

KSY

15 k

Ω

Off Time

Comparator

RSTC/RSTF

Error

Amplifier

Buffer for

Control Voltage

+ +

TDA 16846 TDA 16847

PVC

Primary Voltage

Check

FC2

1.2 V

9 8

REF PMO

FC2

Fold Back Point Correction

x 1/3

PVA

1 V

1.5 V

3.5 V

ED2

Error-

Flipflop

PCS

20 k

Ω

5 V

On Time

Comparator

ED1

1.5 V D1 Startup Diode

< 25 mV

Overvoltage Comparator

GND

The input with the lower voltage becomes operative

16 V

Figure 3 TDA 16847

15/8 V

Zero Crossing

Signal

Supply Voltage

Comparator

On Time

Flipflop

Discharge Time

Flipflop

1 V

FC1

Output

Driver

FC1

AEB02737

OUT

Data Sheet 7 2000-01-14

2 Functional Descript io n

Start Up Behaviour (Pin 14)

TDA 16846

TDA 16847

When power is applied to the c hip and the vol tage

upper threshold (

) of the Supply Voltage Comparator (SVC), input current I14 will be

at Pin 14 (VCC) is less than the

less than 100 µA. The chip is not active and driver output (Pin 13) and cont rol output

(Pin 4) will be actively held low. When

chip starts wor king and

) the chip starts again at his initial condition. Figure 4 shows the start-up circuit and

(

OFF

Figure 5 shows the voltage

increases. When V14 falls below the lower SVC t hreshold

during start up. Charging of C14 is done by resistor R2 of

exceeds the upper SVC threshold (VON) the

the “Primary Current Simu lation” (see later) and t he internal diode D 1, so no additional

start up resistor is needed. The capacitor

delivers the supply current until the

auxiliary windi ng of the transf ormer supplies the chip with curr ent through the e xternal diode D14.

It is recommended to sw itch a sm all RF snubber capacitor of e.g. 100 nF para llel to the electrolytic capacitor at pin 14 as shown in the application circuits in Figures 15, 16, and

17.

D14

PCS

SVC

TDA 16846

Out

AES02649

Figure 4 Startup Circuit

Data Sheet 8 2000-01-14

TDA 16846 TDA 16847

max

Off

Startup Operation

AED02650

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 R2, C2 (Figure 4). The voltage at Pin 2 is forced to 1.5 V when the

power transistor is switched off and during its switch on time

the rectified mains. The relation of

The vol t ag e

: Primary inductance of the transformer

primary

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

and the current in the power transistor (I

1,5 V

primaryIprimary

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

R2C

is charged by R2 from

) is

primary

The other input is the control voltage. If V2 exceeds the control voltage, the driver switches off (curr ent limiting) . The maxi mum val ue of the control voltage is the i nternal reference voltage 5 V, so the maximum current in the power transistor (

Mprimary

) is

3,5 V R2× C2×

Mprimary

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

primary

The control voltage can be reduced by either the Error Amplifier EA (current mode regulation), or by an opto coupler at Pin 5 (re gulation with opto coupler isolation) or by

the voltage

Data Sheet 9 2000-01-14

at Pin 11 (Fold Back Point Correction).

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