LC5901S datasheet(11/29 Pages) SANKEN

Part #	LC5901S

Description	External Phase Compensation is unnecessary

Download	29 Pages

Scroll/Zoom	100%

Manufacturer	SANKEN [Sanken electric]

Direct Link	http://www.sanken-ele.co.jp/en

Logo

11 / 29 page

LC5901S DATA SHEET

Rev.1.5

Copy Right: SANKEN ELECTRIC CO., LTD.

Page.11

fig.8 RRT=47kΩ，VIN=110VDC condition, Number of LED vs. Ton & Frequency

Like this, switching-frequency rises relatively when a "OFF-Period" is set up short. Moreover, when there are

many LED's and VLED is high, it is the character that frequency is decreased because TON spreads out.

7.3 The Setup of reference voltage(VREF)

The reference voltage is set up by the value of the setup resistor RREF that it was connected to between the REF

terminal (pin 8) and GND terminal (pin 3) , and the setup resistor RRT that it was connected to between the RT

terminal (pin 5) and GND terminal (pin 3) . The reference voltage VREF is able to calculate with an equation (6).

The correlation of the reference voltage VREF to the resistance value of RREF is shown as the fig 9. The setup upper

limit voltage of the reference voltage is 2.5V.

Ω

fig.9 the relations of RREF vs. VREF .

Fig 9 is the relations of the reference voltage VREF set up by two resistance of RRT and RREF. By the resistance

detector RCS of fig 3, the IC detects the "average LED current" that is flowing to the LED string and the "average

LED current" is converted as the voltage signals. It is prediction controlled so that the value of the detected voltage

signal may become equal to the reference voltage VREF.

Similar Part No. - LC5901S

Manufacturer	Part #	Datasheet	Description
Seoul Semiconductor	LC590Z	390Kb / 12P	GREEN OVAL LAMP LED

Manufacturer	Part #	Datasheet	Description
Microchip Technology	MIC24053	544Kb / 32P	No External Compensation 11/07/16
Microchip Technology	MIC24051	1Mb / 34P	No External Compensation 11/07/16
KODENSHI_AUK CORP.	KM1102	361Kb / 3P	System clock unnecessary
Renesas Technology Corp	ISL95872	830Kb / 17P	Buck PWM Controller with Internal Compensation and External Reference Tracking
Intersil Corporation	ISL95873	533Kb / 17P	Buck PWM Controller with Internal Compensation and External Reference Tracking
Renesas Technology Corp	ISL95873	835Kb / 17P	Buck PWM Controller with Internal Compensation and External Reference Tracking
Intersil Corporation	ISL95872	617Kb / 17P	Buck PWM Controller with Internal Compensation and External Reference Tracking January 26, 2012
National Semiconductor ...	LM1771	1Mb / 18P	Low-Voltage Synchronous Buck Controller with Precision Enable and No External Compensation
National Semiconductor ...	LM1771_0608	768Kb / 17P	Low-Voltage Synchronous Buck Controller with Precision Enable and No External Compensation
Texas Instruments	LM1771	1Mb / 26P	[Old version datasheet] LM1771 Low-Voltage Synchronous Buck Controller with Precision Enable and No External Compensation