Philips TEA1622P Technical data

查询TEA1622P供应商查询TEA1622P供应商
TEA1622P
STARplug
Rev. 01 — 17 March 2004 Product data sheet
1. General description
The TEA1622P is a Switched Mode Power Supply (SMPS) controller IC that operates directly from the rectified universal mains. It is implemented in the high voltage EZ-HV™ SOI process, combined with a low voltage BICMOS process.
The device includes a high voltagepower switch and a circuit forstart-up directly from the rectified mains voltage. A dedicated circuit for valley switching is built in, which makes a very efficient slim-line electronic power-plug concept possible.
In its most basic version of application, the TEA1622P acts as a voltage source. Here, no additional secondary electronicsarerequired. A combined voltageand current source can be realized with minimum costs for external components. Implementation of the TEA1622P renders an efficient and low cost power supply system.
2. Features
Designed for general purpose supplies
Integrated power switch: 12 and 650 V
Operates from universal AC mains supplies: 80 V to 276 V
Adjustable frequency for flexible design
RC oscillator for load insensitive regulation loop constant
Valley switching for minimum switch-on loss
Frequency reduction at low power output for low standby power: <100 mW
Adjustable overcurrent protection
Undervoltage protection
Temperature protection
Short winding protection
Safe restart mode for system fault conditions
Simple application with both primary and secondary (opto) feedback
Available in 8-pin DIP package.
TM
3. Applications
Adapters VCD
Set-Top Box (STB) ■ CD(R)
DVD PC Silverbox standby SMPS.
Philips Semiconductors
4. Quick reference data
Table 1: Quick reference data
Symbol Parameter Conditions Min Typ Max Unit
V
CC(max)
V
DRAIN(max)
I
DRAIN
R
DSon
f
osc
T
amb
5. Ordering information
TEA1622P
STARplug
maximum supply voltage - - 40 V maximum voltage at pin
DRAIN supply current drawn from
pin DRAIN drain-source on-state
resistance
oscillator frequency range 10 - 200 kHz ambient temperature 20 - +85 °C
Tj>0°C - - 650 V
no auxiliary supply - 0.5 - mA
I
SOURCE
= 0.25 A
=25°C - 12 13.8
T
j
= 100 °C - 17 19.6
T
j
TM
Table 2: Ordering information
Type number Package
Name Description Version
TEA1622P DIP8 plastic dual in-line package; 8 leads (300 mil) SOT97-1
9397 750 12578 © Koninklijke Philips Electronics N.V. 2004. All rights reserved.
Product data sheet Rev. 01 — 17 March 2004 2 of 16
Philips Semiconductors
6. Block diagram
TEA1622P
STARplug
TM
V
CC
GND
RC
REG
1
2
stop
3
OSCILLATOR
low frequency
f
2.5 V
4
1.8 U
10x
TEA1622P
PWM
THERMAL
SHUTDOWN
POWER-UP
RESET
SUPPLY
LOGIC
PROTECTION
LOGIC
overcurrent
short winding
VALLEY
blank
100 mV
0.5 V
8
7
6
5
DRAIN
n.c.
SOURCE
AUX
0.75 V
col009
Fig 1. Block diagram.
7. Pinning information
7.1 Pinning
V
1
CC
GND n.c.
2 3 4
TEA1622P
001aaa309
RC SOURCE
REG AUX
Fig 2. Pin configuration.
9397 750 12578 © Koninklijke Philips Electronics N.V. 2004. All rights reserved.
Product data sheet Rev. 01 — 17 March 2004 3 of 16
8 7 6 5
DRAIN
Philips Semiconductors
7.2 Pin description
Table 3: Pin description
Symbol Pin Description
V
CC
GND 2 ground RC 3 frequency setting REG 4 regulation input AUX 5 input for voltage from auxiliary winding for timing (demagnetization) SOURCE 6 source of internal MOS switch n.c. 7 not connected DRAIN 8 drain of internal MOS switch; input for start-up current and valley sensing
1 supply voltage
8. Functional description
The TEA1622P is the heart of a compact flyback converter, with the IC placed at the primary side. The auxiliary winding of the transformer can be used for indirect feedback to control the isolated output. This additional winding also powers the IC. A more accurate control of the output voltage and/or current can be implemented with an additional secondary sensing circuit and optocoupler feedback.
TEA1622P
STARplug
TM
The TEA1622P uses voltage mode control. The frequency is determined by the maximum transformer demagnetizing time and the time of the oscillator. In the first case, the converter operates in the Self Oscillating PowerSupply (SOPS) mode. In the latter case, it operates at a constant frequency, which can be adjusted with external components R and CRC. This mode is called Pulse Width Modulation (PWM). Furthermore, a primary stroke is started only in a valley of the secondary ringing. This valley switching principle minimizes capacitive switch-on losses.
8.1 Start-up and undervoltage lock-out
Initially, the IC is self supplying from the rectified mains voltage. The IC starts switching as soon as the voltage on pin VCCpasses the V
CC(start)
level. The supply is taken over by the auxiliary winding of the transformer as soon as VCC is high enough and the supply from the line is stopped for high efficiency operation.
As soon as the voltage on pin VCC drops below the V
CC(stop)
level, the IC stops switching
and restarts from the rectified mains voltage.
8.2 Oscillator
The frequency of the oscillator is set by the external resistor and capacitor on pin RC. The external capacitor is charged rapidly to the V stroke, it discharges to the V
level. Because the discharge is exponential, the
RC(min)
RC(max)
relative sensitivity of the duty factor to the regulation voltage at low duty factor is almost equal to the sensitivity at high duty factors. This results in a more constant gain over the duty factor range compared to PWM systems with a linear sawtooth oscillator. Stable operation at low duty factors is easily realized. For high efficiency, the frequency is reduced as soon as the duty factor drops below a certain value. This is accomplished by increasing the oscillator charge time.
leveland, starting from a new primary
RC
9397 750 12578 © Koninklijke Philips Electronics N.V. 2004. All rights reserved.
Product data sheet Rev. 01 — 17 March 2004 4 of 16
Philips Semiconductors
To ensure that the capacitor can be charged within the charge time, the value of the oscillator capacitor should be limited to approximately 1 nF.
8.3 Duty factor control
The duty factor is controlled by the internal regulation voltage and the oscillator signal on pin RC. The internal regulation voltage is equal to the external regulation voltage (minus
2.5 V) multiplied by the gain of the error amplifier (typical 20 dB or 10 ×). The minimum duty factor of the switched mode power supply is 0 %. The maximum duty
factor is set to 75 % (typical value at 100 kHz oscillation frequency).
8.4 Valley switching
A new cycle is started at the primary stroke when the switch is switched on (see Figure 3). After a certain time (determined by the RC oscillator voltage and the internal regulation level), the switch is turned off and the secondary stroke starts. The internal regulation level is determined by the voltage on pin REG. After the secondary stroke, the drain voltage shows an oscillation with a frequency of approximately
Where:
TEA1622P
STARplug
1
------------------------------
2π LpC
×
p
TM
Lp is the primary self inductance on the drain node Cp is the parasitic capacitance on the drain node.
As soon as the oscillator voltage is high again and the secondary stroke has ended, the circuit waits for a low drain voltage before starting a new primary stroke.
The primary stroke starts some time before the actual valley at low ringing frequencies, and some time after the actual valley at high ringing frequencies. Figure 4 shows a typical curve for a reflected voltage N × Vo of 80 V. This voltage is the output voltage Vo (see
Figure 5) transferred to the primary side of the transformer with the factor N (determined
by the turns ratio of the transformer). Figure 4 shows that the system switches exactly at minimum drain voltage for ringing frequencies of 480 kHz, thus reducing the switch-on losses to a minimum. At 200 kHz, the next primary stroke is started at 33° before the valley. The switch-on losses are still reduced significantly.
9397 750 12578 © Koninklijke Philips Electronics N.V. 2004. All rights reserved.
Product data sheet Rev. 01 — 17 March 2004 5 of 16
Loading...
+ 11 hidden pages