ON Semiconductor NCL35076 User manual

CCM Buck Controller for Precise Current Regulation and Wide Analog Dimming

NCL35076

The NCL35076 is a DC−DC buck controller for wide dimming range down to 1% by analog dimming control to relieve audible noise and flicker in PWM dimming. ON Semiconductor’s proprietary LED current calculation technique driven by zero input offset amplifiers performs precise constant current in the whole analog dimming range. Multi−mode operation provides low LED current ripple with small output capacitor by CCM at heavy load and deep analog dimming by DCM at light load.

PWM dimming is also provided in case that constant LED color temperature is required. NCL35076 ensures high system reliability with LED short protection, over current protection and thermal shutdown.

Features

•Wide Analog Dimming Range: 1~100%

•Low CC Tolerance: ±2% at 100% Load & ±20% at 1% Load

•Low System BOM

•LED Off Mode at Standby

•Low Standby Current

•PWM Dimming Available

•Gate Sourcing and Sinking Current of 0.5 A/0.8 A

•Robust Protection Features

♦LED Short Protection

♦Over Current Protection

♦Thermal Shutdown

♦VDD Over Voltage Protection

Typical Applications

• LED Lighting System

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1

SOIC−8 NB

CASE 751

MARKING DIAGRAM

L35076AA

AWLYYWW

L30076 = Specific Device Code

AA	= Default Trimming Option
A	= Assembly Location
WL	= Wafer Lot Traceability Code
YYWW	= 4 Digit Data Code

	PIN ASSIGNMENT
BIAS							PG
CSZCD							DRV
SG							VDD
FB							DIM
				(Top View)
ORDERING INFORMATION
Device				Package			Shipping
NCL35076AADR2G				SOIC−8 NB			3000 /

Tape & Reel

†For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging Specification

Brochure, BRD8011/D.

♥ Semiconductor Components Industries, LLC, 2020	1	Publication Order Number:
April, 2021 − Rev. 2		NCL35076/D

NCL35076

APPLICATION SCHEMATIC

30~200 Vin

VAC

PFC

Flyback

	FB	DRV
Dimming	DIM	CSZCD
Signal
	NCL35076	RCS
	SG	BIAS
	PG	VDD

External source

Figure 1. Application Schematic

BLOCK DIAGRAM

VDD		10 V /	VDD−ON
	3.3 V	8 V		VPDIM	|| VSHUTDOWN
BIAS
	LDO
			VTO FF.SS
		Soft start		VON	VPWM
			VTO FF.FB			DRV
				S	Q
	VFB	Toff generator		VOFF
				R
		OTA			VCS.LIM
		VLED
FB						CSZCD
		VREF
	Reference control		+ 30 mV		Precise LED
				VCS.LIM	current calculator

DIM

PWM dimming control

VPDIM

PG

Standby mode control

VSHUTDOWN

VDD

Over voltage protection

SG

LED short protection

Protection

VSHUTDOWN

AR control

VCSZCD

Over current protection

Thermal Shutdown

TJ

Figure 2. Simplified Block Diagram

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NCL35076

PIN CONFIGURATION

BIAS

PG

CSZCD

DRV

SG

VDD

FB

DIM

(Top View)

Figure 3. Pin Configuration

PIN FUNCTION DESCRIPTION

Pin No.

Pin Name

Function

Description

1

BIAS

3.3 V BIAS

This pin is 3.3 V LDO output to bias the internal digital circuit

2

CSZCD

CS and ZCD Sensing

This pin detects the switch current and the inductor current zero cross time

3

SG

Signal Ground

Signal Ground is close to control pin circuit such as CSZCD, DIM and FB

4

FB

Feedback

Output of feedback OTA

5

DIM

Dimming Input

Dimming signal is provided to this pin

6

VDD

Power Supply

IC operating current is supplied to this pin

7

DRV

Output Drive

This pin is connected to drive external switch

8

PG

Power Ground

Power Ground is close to the capacitors at BIAS and VDD pin

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NCL35076

SPECIFICATIONS

MAXIMUM RATINGS

Parameter	Symbol	Value	Unit
VDD, DRV Pin Voltage Range	VMV(MAX)	−0.3 to 30	V
DIM, FB, CSZCD, BIAS Pin Voltage Range	VLV(MAX)	−0.3 to 5.5	V
Maximum Power Dissipation (TA < 50°C)	PD(MAX)	550	mW
Maximum Junction Temperature	TJ(max)	150	°C
Storage Temperature Range	TSTG	−55 to 150	°C
Junction−to−Ambient Thermal Impedance	RθJA	145	°C/W
ESD Capability, Human Body Model (Note 2)	ESDHBM	2	kV
ESD Capability, Charged Device Model (Note 2)	ESDCDM	1	kV

Stresses exceeding those listed in the Maximum Ratings table may damage the device. If any of these limits are exceeded, device functionality should not be assumed, damage may occur and reliability may be affected.

1.Refer to ELECTRICAL CHARACTERISTICS, RECOMMENDED OPERATING RANGES and/or APPLICATION INFORMATION for Safe

Operating parameters.

2.This device series incorporates ESD protection and is tested by the following methods:

−ESD Human Body Model per JEDEC Standard JESD22−A114

−ESD Charged Device Model per JEDEC Standard JESD22−C101

−Latch−up Current Maximum Rating ±100 mA per JEDEC Standard JESD78

RECOMMENDED OPERATING RANGES

Parameter	Symbol	Min	Max	Unit
Junction Temperature	TJ	−40	125	°C

Functional operation above the stresses listed in the Recommended Operating Ranges is not implied. Extended exposure to stresses beyond the Recommended Operating Ranges limits may affect device reliability.

ELECTRICAL CHARACTERISTICS (VDD = 15 V and TJ = −40~125°C unless otherwise specified)

Parameter	Test Conditions	Symbol	Min	Typ	Max	Unit
VDD SECTION
IC Turn−On Threshold Voltage		VDD(ON)	9.3	10.0	10.7	V
IC Turn−Off Threshold Voltage		VDD(OFF)	7.4	8.0	8.6	V
Startup Current	VDD = VDD(ON) − 1.6 V	IDD(ST)	−	250	400	mA
Operating Current		IDD(OP)	−	6.5	8.0	mA
Standby Current		IDD(SB)	−	200	300	mA
BIAS SECTION
BIAS Voltage		VBIAS	3.23	3.30	3.37	V
	TJ = 25~100°C (Note 4)		3.25	3.30	3.35	V
DIM SECTION
DIM Voltage for 100% VREF	VDIM = 2.6 V	VDIM(REF−MAX)	2.44	2.50	2.56	V
DIM Voltage for 99% VREF		VDIM(MAX−EFF)	2.400	2.475	2.528	V
Standby Enabling DIM Voltage		VDIM(SB−ENA)	50	75	100	mV
Standby Disabling DIM Voltage		VDIM(SB−DIS)	60	100	140	mV
Standby Delay Time		tSB(DELAY)	9	10	11	ms
FB SECTION
FB OTA Source Current	IFB = (VLED − VREF) x gM(FB) x 12.5	IFB(SOURCE)	−14.0	−11.5	−9.0	mA
	VREF = 120 mV, VLED = 80 mV
FB OTA Sink Current	IFB = (VLED − VREF) x gM(FB) x 12.5	IFB(SINK)	9.0	11.5	14.0	mA
	VREF = 40 mV, VLED = 80 mV

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NCL35076

ELECTRICAL CHARACTERISTICS (VDD = 15 V and TJ = −40~125°C unless otherwise specified) (continued)

Parameter	Test Conditions	Symbol	Min	Typ	Max	Unit
FB SECTION
FB OTA Transconductance	gM(FB) = IFB / {(VREF − VLED) x 12.5}	gM(FB)	18	23	28	mmho
FB OTA High Voltage	VREF = 120 mV, VLED = 80 mV	VFB(HIGH)	4.7	−	−	V
FB Minimum Clamping Voltage	VREF = 0 mV, VLED = 80 mV	VFB(CLP)	0.4	0.5	0.6	V
CS SECTION
CS Regulation		VCS(REG−MAX)	175	180	185	mV
CS Current Ripple Voltage		VCS(RIPPLE)	25	30	35	mV
CS Current Limit Minimum		VCS(LIM−MIN)	72	80	88	mV
DUTY SECTION
Leading Edge Blanking Time at		tLEB(TON)	360	400	440	ns
Turn−on
Maximum Ton Time		tON(MAX)	45	50	55	ms
Minimum Toff Time	VFB = 3.8 V	tOFF(MIN)	400	850	1000	ns
Maximum Toff Time	VFB = 0.5 V	tOFF(MAX)	1.17	1.30	1.43	ms
Maximum FB Voltage for Min. Toff		VFB(MAX−TOFF)	3.30	3.43	3.55	V
Minimum FB Voltage for Max. Toff		VFB(MIN−TOFF)	0.9	1.1	1.3	V
DRV SECTION
DRV Low Voltage		VDRV(LOW)	−	−	0.2	V
DRV High Voltage	VDD = 15 V	VDRV(HIGH)	11	12	13	V
DRV Rising Time	CDRV = 3.3 nF	tDRV(R)	60	100	145	ns
DRV Falling Time	CDRV = 3.3 nF	tDRV(F)	25	55	105	ns
AUTO RESTART SECTION
Auto Restart Time at Protection		tAR(PROT)	0.9	1.0	1.1	s
VDD OVER VOLTAGE PROTECTION SECTION
VDD Over Voltage Threshold Voltage		VDD(OVP)	22	23	24	V
SHORT LED PROTECTION SECTION
SLP Monitoring Triggering Delay		tSLP(MON−DEL)	18	20	22	ms
Time
SLP Monitoring Disable Time at		tSLP(MON−DIS)	10.8	12.0	13.2	ms
Startup
OVER CURRENT PROTECTION SECTION
CS Over Current Protection Thresh-		VCS(OCP)	0.4	0.5	0.6	V
old
THERMAL SHUTDOWN SECTION
Thermal Shut Down Temperature		TSD	130	150	170	°C
(Note 3)
Thermal Shut Down Hysteresis		TSD(HYS)	25	30	35	°C
(Note 3)

Product parametric performance is indicated in the Electrical Characteristics for the listed test conditions, unless otherwise noted. Product performance may not be indicated by the Electrical Characteristics if operated under different conditions.

3.Guaranteed by design.

4.Guaranteed by characterization.

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