TOP210 Ver la hoja de datos (PDF) - Power Integrations, Inc

Número de pieza

componentes Descripción

Fabricante

TOP210

Three-terminal Off-line PWM Switch

Power Integrations, Inc 

TOP209/210

General Circuit Description

Figure 7 shows a low-cost, DC input, flyback switching power

supply using the TOP210 integrated circuit. This 5 V, 4 W

power supply operates from a DC voltage derived from rectified

and filtered AC mains voltage of 85 to 265 VAC. The 5 V

output is indirectly sensed via the primary bias winding. The

output voltage is determined by the TOPSwitch CONTROL pin

shunt regulator voltage (VC), the voltage drops of rectifiers D2

and D3, and the turns ratio between the bias winding and output

winding of T1. Other output voltages are also possible by

adjusting the transformer turns ratios.

The high voltage DC bus is applied to the primary winding of

T1. Capacitor C1 filters the high voltage supply, and is only

necessary if the connections between the high voltage DC

supply and the TOP210 are long. The other side of the

transformer primary is driven by the integrated high-voltage

MOSFET within the TOP210. D1 and VR1 clamp the voltage

spike caused by transformer leakage inductance to a safe value

and reduce ringing at the DRAIN of U1. The power secondary

winding is rectified and filtered by D2, C2, L1, and C3 to create

the 5V output voltage. The bias winding is rectified and filtered

by D3, R1 and C5 to create a bias voltage to the TOP210. C5

also filters internal MOSFET gate drive charge current spikes

on the CONTROL pin, determines the auto-restart frequency,

and together with R1, compensates the control loop.

D2

L1

1N5822

3.3 µH

1

8

+5 V

+

VR1

BZY97-

C120

120 V

C2

330 µF

10 V

C3

100 µF

10 V

5

D1

RTN

UF4005

D3

1N4148

2

4

DC

INPUT

C1

10 nF

400 V

3

T1

R1

15 Ω

2

-

D

TOPSwitch

CONTROL

C

S U1

TOP210

TRD1

C5

47 µF

10 V

CIRCUIT PERFORMANCE:

Line Regulation - –1.5%

(104-370 VDC)

Load Regulation - –5%

(10-100%)

Ripple Voltage –25 mV

Figure 7. Schematic Diagram of a Minimum Parts Count 5 V, 4 W Bias Supply Using the TOP210.

PI-2045-041798

6A

8/97

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