PWM Regulators Guide

 

PWM IPS in the housings SOT-23-6, SOT-26, TSOP-6

By Imran Ashraf Khan

In the circuitry of modern pulsed power supplies (SMPS), PWM regulators, made in small-sized planar cases with six terminals, have gained wide popularity. The body type designation can be SOT-23-6, SOT-23-6L, SOT-26, TSOP-6, SSOT-6. The layout and layout of the pins are shown in the figure below. In this case, the left fragment of the picture shows the code marking LD7530A

Pin Assignment: 
1 - GND. (Common wire). 
2 - FB. (FeedBack - Feedback). Input for controlling the pulse duration with a signal from the output voltage. Sometimes it can have the designation COMP (input comparator). 
3 - RI / RT / CT / COMP / NC - Depending on the type of chip, it can be used for a frequency-assigning RC circuit (RI / RT / CT) or for protection, as a PWM tripping comparator input with a threshold value at its input, specified in the document. In some types of microcircuits this input can be not involved in any way (NC - No Connect). 
4 - SENSE, different CS (Current Sense) - Input from the current sensor at the source of the key. 
5 - VCC - Input voltage supply and start the chip. 
6th - OUT (GATE) - Output to control the gate of the key.

Functionally similar regulators work on the principle of popular earlier PWM chips xx384x series, which have proved themselves in terms of reliability and stability.

Some difficulties often arise when replacing or selecting an analog for similar PWM controllers due to the use of code marking in the designation of the type of microcircuit. The situation is complicated by a large number of component manufacturers, which do not always provide documentation for mass access, and not all manufacturers of ready-made devices supply repair service centers with circuits, so real repair schemes often have to be studied by repairers on the installed components and wiring connections directly on the board.

In practice, PWM chips and EAxxx and Eaxxx marking codes are often found. Official documents on them are not found in free access, but discussions on the forums and pieces of pictures from the PDF from System General, which publishes them as SG6848T and SG6848T2, have been preserved. The picture is attached.

To the attention of the masters we offer tables made up of information available on the Internet and PDF documents for the selection of analogs when replacing the most common six-legged planar PWM with pinout: pin1 - GND, pin2 - FB (COMP), pin4 - Sense, pin5 - Vcc, pin6 - OUT . 
Their main difference is the application and purpose of the output 3.

PWM controllers (PWM), without using output 3.

Name	Part Namber	Diler	Marking
SG6849	SG684965TZ	Fairchild / ON Semi	BBxx
SG6849	SG6849-65T, SG6849-65TZ	System General	MBxx EBxx
SGP400	SGP400TZ	System General	AAKxx

PWM-regulators (PWM) with the installation of the resistor 95-100 kOhm to pin 3.

Using the PWM listed below, the frequency should be set by the resistor RT (RI) from pin 3 to ground. Usually its rating is chosen 95-100 kOhm for frequency 65-100 KHz. More precisely see the attached documentation. PDF files are packaged in RAR.

Name	Part Namber	Diler	Marking
AP3103A	AP3103AKTR-G1	Diodes Incorporated	GHL
AP8263	AP8263E6R, A8263E6VR	AiT Semiconductor	S1xx
AT3263	AT3263S6	ATC Technology	3263
CR6848	CR6848S	Chip-Rail	848H16
CR6850	CR6850S	Chip-Rail	850xx
CR6851	CR6851S	Chip-Rail	851xx
FAN6602R	FAN6602RM6X	Fairchild / ON Semi	ACCxx
FS6830	FS6830	FirstSemi
GR8830	GR8830CG	Grenergy	30xx
GR8836	GR8836C, GR8836CG	Grenergy	36xx
H6849	H6849NF	HI-SINCERITY
H6850	H6850NF	HI-SINCERITY
HT2263	HT2263MP	HOT-CHIP	63xxx
KP201		Kiwi Instruments
LD7531	LD7531GL, LD7531PL	Leadtrend	xxP31
LD7531A	LD7531AGL	Leadtrend	xxP31A
LD7535 / A	LD7535BL, LD7535GL, LD7535ABL, LD7535AGL	Leadtrend	xxP35-xxx35A
LD7550	LD7550BL, LD7550IL	Leadtrend	xxP50
LD7550B	LD7550BBL, LD7550BIL	Leadtrend	xxP50B
LD7551	LD7551BL / IL	Leadtrend	xxP51
LD7551C	LD7551CGL	Leadtrend	xxP51C
NX1049	XN1049TP	Xian-Innuovo	49xxx
OB2262	OB2262MP	On-Bright-Electronics	62xx
OB2263	OB2263MP	On-Bright-Electronics	63xx
PT4201	PT4201E23F	Powtech	4201
R7731	R7731GE / PE	Richtek	0Q =
R7731A	R7731AGE	Richtek	IDP = xx
SD4870	SD4870TR	Silan Microelectronics	4870
SF1530	SF1530LGT	SiFirst	30xxx
SG5701	SG5701TZ	System General	AAExx
SG6848	SG6848T, SG6848T1, SG6848TZ1, SG6848T2	Fairchild / ON Semi	AAHxx EAxxx
SG6858	SG6858TZ	Fairchild / ON Semi	AAIxx
SG6859A	SG6859ATZ, SG6859ATY	Fairchild / ON Semi	AAJFxx
SG6859	SG6859TZ	Fairchild / ON Semi	AAJMxx
SG6860	SG6860TY	Fairchild	AAQxx
SP6850	SP6850S26RG	Sporton Lab	850xx
SP6853	SP6853S26RGB, SP6853S26RG	Sporton Lab	853xx
SW2263	SW2263MP	SamWin
UC3863 / G	UC3863G-AG6-R	Unisonic Technologies Co	U863 U863G

PWM controllers in which pin 3 is used differently.

When using the PWM controllers listed below, you should pay attention to pin 3, which can be used to organize protection - thermal or from exceeding the input voltage. 
The frequency can be fixed at 65kHz, or be set by the capacitor rating on pin 3. 
When replacing any microcircuits with analogs, carefully study the documentation. PDF files are packed in the RAR archive.

Name	Part Namber	Diler	Marking
AP3105 / V / L / R	AP3105KTR-G1, AP3105VKTR-G1, AP3105LKTR-G1, AP3105RKTR-G1	Diodes Incorporated	GHN GHO GHP GHQ
AP3105NA / NV / NL / NR	AP3105NAKTR-G1, AP3105NVKTR-G1, AP3105NLKTR-G1, AP3105NRKTR-G1	Diodes Incorporated	GKN GKO GKP GKQ
AP3125A / V / L / R	AP3125AKTR-G1, AP3125VKTR-G1, AP3125LKTR-G1, AP3125RKTR-G1	Diodes Incorporated	GLS GLU GNB GNC
AP3125B	AP3125BKTR-G1	Diodes Incorporated	GLV
AP3125HA / HB	AP3125HAKTR-G1, AP3125HBKTR-G1	Diodes Incorporated	GNP GNQ
AP31261	AP31261KTR-G1	Diodes Incorporated	GPE
AP3127 / H	AP3127KTR-G1, AP3127HKTR-G1	Diodes Incorporated	GPH GSH
AP3301	AP3301K6TR-G1	Diodes Incorporated	GTC
FAN6862	FAN6862TY	Fairchild / ON Semi	ABDxx
FAN6863	FAN6863TY, FAN6863LTY, FAN6863RTY	Fairchild / ON Semi	ABRxx
HT2273	HT2273TP	HOT-CHIP	73xxx
LD7510 / J	LD7510GL, LD7510JGL	Leadtrend	xxP10 xxP10J
LD7530 / A	LD7530PL, LD7530GL, LD7530APL, LD7530AGL	Leadtrend	xxP30 xxxP30A
LD7532	LD7532GL	Leadtrend	xxP32
LD7532A	LD7532AGL	Leadtrend	xxP32A
LD7532H	LD7532HGL	Leadtrend	xxP32H
LD7533	LD7533GL	Leadtrend	xxP33
LD7536	LD7536GL	Leadtrend	xxP36
LD7536R	LD7536RGL	Leadtrend	xxP36R
LD7537R	LD7537RGL	Leadtrend	xxP37R
ME8204	ME8204M6G	MicrOne	ME8204xx
NCP1250	NCP1250ASN65T1G, NCP1250BSN65T1G, NCP1250ASN100T1G, NCP1250BSN100T1G	ON Semiconductor	25xxxx
NCP1251	NCP1251ASN65T1G, NCP1251BSN65T1G, NCP1251ASN100T1G, NCP1251BSN100T1G	ON Semiconductor	5xxxxx
OB2273	OB2273MP	On-Bright-Electronics	73xx
R7735	R7735AGE, R7735HGE, R7735GGE, R7735RGE, R7735LGE	Richtek
UC3873 / G	UC3873-AG6-R, UC3873G-AG6-R	Unisonic Technologies	U873 U873G

The table is updated as information becomes available.

How to read LDO LCD 8-pin regulator code 00HC5W

• This kind of regulator is often found on the Toshiba LCD motherboard, and the shape is similar to ic eeprom.
• The BD writing code is not written on the physical ic regulator. So for example just written 00IC0W, 00IA5W

How to read the specs: For example say 00HC5W

(1) Code "00" This means that the output voltage variable or can diajust by changing the value of the feedback resistor. 
(2) The "H" code indicates that the maximum input allowable voltage is 10v. 
(3) The code "C5" indicates that the maximum current capability of 1.5A 

Example usage:

• Input Voltage: 8.0v
• Output voltage: 1.5v to 7v - can be obtained by changing the value of R1 / R2

 

6 pin Regulator SMD Chip Codes
6 pin PWM IC code
5xy= NCP1251,
IDP606 = R7731A,
63xxx = OB2263,
WP35/XP35 = LD7535,
ABx = FAN6862,
xxP/50 = LD7550IL_BL,
xxP/50 = LD7550IL_BL
52xxx = OB2252
62xxx = OB2262
73xxx = 0B2273
AAIxx = SG6858TZ
G6G = AP4313
37x = LD7537

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