SSL1623PH_1

© NXP B.V. 2008. All rights reserved.

Product data sheet

Rev. 01 — 15 September 2008

4 of 15

NXP Semiconductors

SSL1623PH

7.

Pinning information

7.1 Pinning

7.2 Pin description

8.

Functional description

The SSL1623PH 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 opto coupler feedback. The SSL1623PH can be used in a

constant power mode or in a constant current mode to drive LEDs.

The SSL1623PH 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 Power Supply (SOPS) mode. In the latter

Fig 2.

Pin configuration

SSL1623PH

n.c.

n.c.

n.c.

n.c.

DRAIN

GND

n.c.

RC

SOURCE

REG

AUX

n.c.

n.c.

SGND

n.c.

014aaa345

1

2

3

4

5

6

7

8

10

9

12

11

14

13

16

15

Table 3.

Pin description

Symbol

Pin

Description

3

supply voltage

GND

4

ground

RC

5

frequency setting

REG

6

regulation input

SGND

8

signal ground; must preferably be connected to pin GND

AUX

11

input for voltage from auxiliary winding for timing (demagnetization)

SOURCE

12

source of internal MOS switch

n.c.

1, 2, 7, 9, 10,

13, 15, 16.

not connected

DRAIN

14

drain of internal MOS switch; input for start-up current and valley

sensing