SYSTEM GENERAL SG6108 Product Specification

Product Specification

Power Supply Supervisor + PWM SG6108

+

Main Transfor mer

5Vsb

Pok

Pson

Vdd

12V

5V

-5V

-12V

3.3V

5V

12V

-12V

UVAC IS12

Vcc

PG

IS5

IS33

V33

V5

V12

VS12B

Pson

OP1

NVP

RI

GND

IN

COMP

SS

OP2

OPP

SG6108

FEATURES

 PC half-bridge (or 494) power supply supervisor +

PWM

 Highly Integrated and Few external components

required

 Over voltage protection 3.3V/5V/12V (two 12V)  Under voltage protection 3.3V/5V/12V (two 12V)  Under voltage protection for –12V and/or –5V  Over current protection 3.3V/5V/12V (two 12V)  Over power protection  Short circuit protection  Power-down warning circuitry  Power good circuitry  Delay time for PSON and PG signals  Remote ON/OFF function  On-Chip oscillator and Error amplifier  Latching PWM for cycle-by-cycle switching  Soft-start  Maximum 48% duty cycle

APPLICATIONS

Switching mode power supplies for computers such

as ATX, NLX, and SFX (micro-ATX).

DESCRIPTION

The SG6108 controller is designed for desktop PC switching mode power supplies. It provides everything necessary to monitor and control the output of the power supply. Remote ON/OFF control, power good circuitry, over-voltage protection, over-power protection, and over-current protection are all included. The SG6108 directly senses all the output rails for over voltage conditions without requiring external dividers. An innovative AC-signal sampling circuit provides an adequate power-down warning signal for PG. A built-in timer generates accurate timing for the control circuit.

Cycle-by-cycle PWM switching protects the power transformer from saturation and ensures a rapid response for short-circuit protection. This greatly reduces the stress on the power transistors. The SG6108 utilizes a minimum number of external components while including all the functions needed for push-pull and/or half-bridge topologies. This decreases production costs and PCB space while increasing the power supply’s MTBF.

TYPICAL APPLICATION

查询SG6108DZ供应商

Product Specification

Power Supply Supervisor + PWM SG6108

1 2

3

4

5

6

7

8

9

10

20 19

18

17 16

15

14

13

12

11

PSON

V33

V5

OPP

UVAC

NVP

VS12

OP2 OP1

PG

VS12B

IS12

IS5

IS33

GND

COMP

IN

SS

RI

VCC

MARKING DIAGRAMS P I N CONFIGURATION

ORDERING INFORMATION

Part Number Pb-Free Package

SG6108DZ

20-Pin DIP

T : D = DIP P : Z = Lead Free

Null=regular package

XXXXXXXX: Wafer Lot Y: Year; WW: Week V: Assembly Location

20

1

SG6

108

TP

XXXXXXXXYWWV

Product Specification

Power Supply Supervisor + PWM SG6108

PIN DESCRIPTIONS

Name Pin Type Function

PSON 1 Logic Input

Remote On/Off logic input for the CPU or the controller. Turns the PWM output on/off following a 45

msec / 16 msec delay.

PSON = 0 means that the main SMPS is operational.

PSON =1 means that the main SMPS is off and the latch is reset.

V33 2 Analog Input 3.3V over-voltage/under-voltage control sense input.

V5 3 Analog Input 5V over-voltage/under-voltage control sense input.

OPP 4 Analog Input

Over-power sense input. This pin is connected to the driver transformer or the output of the current

transformer. When not in use, this pin should be grounded.

UVAC 5 Analog Input AC fail-detection. This detects main AC voltage under-voltage and/or failure.

NVP 6 Analog Input The protection input for negative outputs, such as –12V and/or –5V. Trip voltage = 2.1V.

VS12 7 Analog Input 12V over-voltage/under-voltage control sense input.

OP2/OP1 8/9 Analog Output

The totem-pole output drivers of a push-pull PWM. The outputs are enabled (low) only when the

NAND gate inputs are high. The maximum duty cycle on an output (OP1 or OP2) is 48%.

PG 10 Logic Output

Power Good logic output, 0 or 1 (open-collector). PG = 1 means that the power is good for operation.

The PG delay is 300 msec.

VS12B 11 Analog Input Second 12V over-voltage/under-voltage control sense input.

IS12 12 Analog Input 12V over current protection sense input. The sink current = 8 x IRI

IS5 13 Analog Input 5V over current protection sense input. The sink current = 8 x IRI

IS33 14 Analog Input 3.3V over current protection sense input. The sink current = 8 x IRI

GND 15 Supply Ground.

COMP 16 Analog Output The error amplifier output and the input of the PWM comparator.

IN 17 Analog Input

The negative input of the error amplifier. The positive input of the error amplifier is a 2.5V reference

voltage.

SS 18 Analog Input

Soft-start. This can be set through the external capacitor. The current source output at this pin is 8uA

and the voltage is clamped at 2.5V.

RI 19

Program.

Analog Input

This is connected to the external resistor to provide a reference setting. It determines the PWM

frequency, and also the OCP current setting. Setting RI = 75kΩ will result in a PWM frequency of

65kHz. Do not attach a capacitor to this pin. For OCP current settings please refer to the Over Current

Protection section on page 13.

VCC 20 Supply Supply voltage. 4.5V ~ 5.5V. It is connected to the 5V-standby.

Product Specification

Power Supply Supervisor + PWM SG6108

BLOCK DIAGRAM

Product Specification

Power Supply Supervisor + PWM SG6108

TIMING DIAGRAM

VCC

PSON

3.3V,5V,12V

t

pson(on)

t

uvp

NVP

t

pson(off)

t

nvp

SS(on/off)

t

psoff

PG

t

PG

VCC

PSON

Voltage < V

UVAC

t

OPP

SS(on/off)

PG

Product Specification

Power Supply Supervisor + PWM SG6108

ABSOLUTE MAXIMUM RATINGS

Symbol Parameter Value Unit

V

CC, MAX

DC Supply Voltage at Pin 20 6 V

I

OUT

Input Current at PG,FB Pins 30 mA

OP1, OP2, VS12, VS12B, IS12 -0.3 to 16 V V

PIN, MAX

OPP, UVAC, RI, SS, PG, IN, COMP, FB, NVP, IS5, V33, V5, PSON -0.3 to 7 V

P

D,25

℃

Power Dissipation (TA=25℃) 1.5 W

P

D,90

℃

Power Dissipation (TA=90℃) 0.5 W

T

STG

Storage Temperature Range -55 to +150 ℃

R

θJA

Thermal Resistance, Junction-To-Case 28.58 ℃/W

T

J,MAX

Operating Junction Temperature 150 ℃

T

A,MAX

Operating Ambient Temperature -20 to +85 ℃

T

L

Lead Temperature (Wave soldering or IR, 10seconds) 260 ℃

ESD Capability, HBM model 3.0 KV

ESD Capability, Machine model 200 V

* All voltage values, except the differential voltage, are given with respect to the network ground terminal.

* Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device.

RECOMMENDE D OPERA TIN G COND ITION S

Symbol Parameter Value Unit

V

CC

DC Supply Voltage 4.5 to 5.5 V

TA Operating Ambient Temperature -20 to +85 ℃

* For proper operation

Electrical Characteristics (VCC=5V, TA = 25°C,RI=75Kohm,unless noted) VCC Section

Symbol Parameter Test Condition Min. Typ. Max. Unit

I

CC1

Total Supply Current PSON=Low,

OP1/OP2 1000pF

10 mA

I

CC2

Total Supply Current PSON=High,

OP1/OP2 1000pF

5 10 mA

Product Specification

Power Supply Supervisor + PWM SG6108

Protection Section

Symbol Parameter Test Condition Min. Typ. Max. Unit

V

OVP1

Over-Voltage Protection 3.3V 3.9 4.1 4.3 V

V

OVP2

Over-Voltage Protection 5V 5.8 6.1 6.5 V

V

OVP3

Over-Voltage Protection VS12,VS12B 13.75 14.05 14.35 V

V

UVP1

Under-Voltage Protection 3.3V 2.0 2.6 2.8 V

V

UVP2

Under-Voltage Protection 5V 3.0 3.6 3.9 V

V

UVP3

Under-Voltage Protection VS12,VS12B 6.0 7.2 8.0 V

V

UVS1

Under-Voltage Sense 3.3V for PG Low 2.5 2.8 3.0 V

V

UVS2

Under-Voltage Sense 5V for PG Low 4.0 4.3 4.5 V

V

UVS3

Under-Voltage Sense VS12,VS12B for PG Low 9.4 10.1 10.4 V

V

OPP

* 1 Over-Power Protection (With T

OPP

delay time) V

UVAC

= 1.5V 2.23 2.3 2.37 V

V

OPPH

Over-Power Protection (Without delay time) 3.0 3.2 3.4 V

VX

Disable Under Voltage / Over Power Protection

threshold

0.2 0.3 0.4 V

V

NVP

Negative Voltage Protection: Voltage Level 2.0 2.1 2.2 V

I

NVP

Negative Voltage Protection: Source Current 57 64 72 uA

T

UVEDA

Under Voltage Enable Delay Time VS12/B = 0.8V 10 17 22 mS

T

UVEDB

Under Voltage Enable Delay Time VS12/B = 5V 22 30 40 mS

T

OVP

Timing for Over-Voltage Protection 0.37 0.7 1.35 mS

T

UVP

Timing for Under-Voltage Protection 1.2 2.7 4.2 mS

T

UVS

Timing for Under-Voltage Sense (PG Low) 0.9 1.6 2.2 mS

T

OPP

Timing for Over-Power-Protection 4 6 8 mS

T

NVP

Timing for Negative Voltage Protection 3.3 7 10.2 mS

T

OCP

Timing for Over-Current Protection 15 20 25 mS

SS go Hi, VS12/B=0.8V

10 17 22

T

OCP(EN)

Timing for Over-Current Protection Function Enable

SS go Hi, VS12/B =5V 22 30 40

mS

V

OFFSET

OCP Comparator Input Offset Voltage -5 5 mV

I

REF

Ratio of IS33, IS5, IS12 to RI Current Setting 7.6 8 8.4

I

LK33

V33 Leakage Current V33 = 3.3V 50 uA

I

LK5

V5 Leakage Current V5= 5V 50 uA

I

LK12AB

VS12, VS12B Leakage Current

VS12 =12V VS12B = 12V

50 uA

Note *1: V

OPP

= (2/3) x V

OPP

+ (1/3) x V

UVAC

;

Power Good Section

Symbol Parameter Test Condition Min. Typ. Max. Unit

TPG Timing for PG Delay 200 300 400 mS

T

UVAC

Timing for PG Fail UVAC to PG 75 150 300 uS

V

UVAC

UVAC Voltage Sense for PG 0.68 0.7 0.72 V

V

UVAC(DIS)

Disable UVP,NVP,OCP Voltage 0.68 0.7 0.72 V

T

UVAC(DIS)

Timing for Disable UVP,NVP,OCP UVAC < V

UVAC(DIS)

75 150 300 uS

T

UVAC(EN)

Timing for Enable UVP,NVP,OCP UVAC > V

UVAC(DIS)

15 25 35 mS

T

R

*2

PG Output Rising Time

CL =100pF Pull 2.2K to

5V

1 3 uS

T

F

*2

PG Falling Time

CL =100pF Pull 2.2K to

5V

300 500 nS

V

OL2

Power Good Output Saturation Level IPG = 5mA 0.5 V

I

IO2

Power Good Leakage Current VPG = 5V 1 uA

Note *2: Not tested in production test;

Product Specification

Power Supply Supervisor + PWM SG6108

Remote On/Off

Symbol Parameter Test Condition Min. Typ. Max. Unit

V

PSON

PSON Input Threshold Level 1 1.4 2.0 V

I

PSON

Remote Input Driving Current 0.5 mA

T

PSON(ON)

T

PSON(OFF)

PSON to On/Off Time

On

Off

25

8

45

16

65

24

mS

T

PSOFF

PG Low to Power Off Time 1.5 2 6.3 mS

Error Amplifier

Symbol Parameter Test Condition Min. Typ. Max. Unit

V

2.5

Reference Voltage 2.45 2.5 2.55 V

I

IB

*2

Input Bias Current 0.1 uA

V

DEV,T2.5

*2

Deviation of V

2.5

Over Temperature 10 30 mV

I

COSI

I

COMP

Source Current IN Short COMP

VCOMP=2.4V

0.4 mA

I

COSO

I

COMP

Sink Current IN Short COMP

VCOMP=2.6V

1.2 mA

A

VOL

* 2

Open-Loop Voltage Gain 50 60 dB

BW

* 2

Unity Gain Bandwidth 0.3 1 MHz

PSRR

* 2

Power Supply Rejection Ratio 50 dB

Oscillator Section

Symbol Parameter Test Condition Min. Typ. Max. Unit

F

OSC

PWM Frequency 60 65 70 KHz

DC

MAX

Max Duty Cycle 41 44.5 48 %

RI RI Resistor Range 70 105 KΩ

V

REFRI

RI Reference Voltage 0.98 1 1.02 V

T

DEAD

PWM Dead Time 1.3 1.7 2.1 uS

Soft-Start Section

Symbol Parameter Test Condition Min. Typ. Max. Unit

ISS Charge Current 6.7 8 9.3 uA

I

SSINK

Sink Current 1 mA

PWM Output Section (OP1, OP2)

Symbol Parameter Test Condition Min. Typ. Max. Unit

VOL Output Voltage Low Io = 20mA 1 V

VOH Output Voltage High VDD = 5V 4 V

RO Output Impedance of VOH 0.8 2.6 kΩ

Product Specification

Power Supply Supervisor + PWM SG6108

TYPICAL CHARACTERISTICS

Total Supply Current (I

CC1

) vs Tem perature

0

3

5

8

10

13

15

-40 -25 -10 5 20 35 50 65 80 95 110 125

Temperature (℃)

I

CC1

(mA )

Over-Power Protection (With TOPP delay time)

(V

OPP

* 1) vs Temperature

2.23

2.25

2.27

2.29

2.31

2.33

2.35

2.37

-40 -25 -10 5 20 35 50 6 5 80 95 1 10 125

Temperature (℃)

V

OPP

*

1

(V)

Over P ower Protection (Without delay time) (V

OPPH

)

vs Temperature

3.0

3.1

3.2

3.3

3.4

-40 -25 -10 5 20 35 50 65 80 95 110 125

Temperature (℃)

V

OPPH

(V)

Negative Voltage Protection: Voltage Level (V

NVP

) vs

Temperature

1.0

1.5

2.0

2.5

3.0

3.5

-40 -25 -10 5 20 35 50 65 80 95 110 125

Temperature (℃)

V

NVP

(V)

Negative Voltage Protec tion: Source Current (I

NVP

)

vs Temperature

64

65

66

67

68

69

-40 -25 -10 5 20 35 50 65 80 95 110 125

Temperature (℃ )

I

NVP

(uA)

Timing for Over-Power-Protection

(T

OPP

) vs Temperature

4.0

4.5

5.0

5.5

6.0

6.5

7.0

7.5

8.0

-40 -25 -10 5 20 35 50 65 80 95 110 125

Temperature (℃)

T

OPP

(

mS)

Product Specification

Power Supply Supervisor + PWM SG6108

Timing for Ov er-Current Protection (T

OCP

) vs

Temperature

15

17

19

21

23

25

-40 -25 -10 5 20 35 50 65 80 95 110 125

Temperature (℃ )

T

OCP

(mS)

OCP Com parator Input Offset Voltage (V

OFFSET

) vs

Temperature

-5.0

-3.0

-1.0

1.0

3.0

5.0

-40 -25 -10 5 20 35 50 65 80 95 110 125

Temperature (℃)

V

OFFSET

(mV)

Ratio of IS12 to R I Curren t Setting ( I

REF

) vs

Temperature

7.7

7.8

7.9

8.0

8.1

8.2

8.3

8.4

-40 -25 -10 5 20 35 5 0 65 80 95 110 12 5

Temperature (℃ )

I

REF

VS12 Leakage Current (I

LK12AB

_VS12 ) vs

Temperature

15

16

17

18

19

20

-40 -25 -10 5 20 35 50 65 80 95 1 10 125

Temperature (℃)

I

LK12AB

_VS12 (uA)

VS12B Leak age Current ( I

LK12AB

_VS12B) vs

Temperature

15

16

17

18

19

20

-40 -25 -10 5 20 35 50 65 80 95 110 125

Temperature (℃)

I

LK12AB

_VS12B (uA)

UVAC Volta ge Se nse fo r PG ( V

UVAC

) vs Temperature

0.68

0.69

0.70

0.71

0.72

-40 -25 -10 5 20 35 50 65 80 95 11 0 1 25

Temperature (℃)

V

UVAC

(V)

Product Specification

Power Supply Supervisor + PWM SG6108

Reference Voltage (V

2.5

) vs Temper ature

2.45

2.47

2.49

2.51

2.53

2.55

-40 -25 -10 5 20 35 50 65 80 95 110 125

Temperature (℃)

V

2.5

(V)

PWM Frequency (F

OSC

) vs Temperature

60

62

64

66

68

70

-40 -25 -10 5 20 35 50 65 80 95 110 125

Temp erature (℃ )

F

OSC

(KHz )

Max Duty Cycle (DC

MAX

) vs Temperature

42

43

44

45

46

47

-40 -25 -10 5 20 35 50 65 80 95 110 125

Temperature (℃)

DC

MAX

(%)

RI Reference Voltage (V

REFRI

) vs Tempera ture

0.98

0.99

1.00

1.01

1.02

-40 -25 -10 5 20 35 50 65 80 95 110 125 Temperature (℃)

V

REFRI

(V)

PWM Dead Time (T

DEAD

) vs Temperature

1.3

1.4

1.5

1.6

1.7

1.8

-40 -25 -10 5 20 35 50 65 80 95 110 125

Temperature (℃)

T

DEAD

(uS)

Charge C urrent (ISS) vs Temperature

7.4

7.6

7.8

8.0

8.2

8.4

8.6

-40 -25 -10 5 20 35 50 65 80 95 110 125

Temperature (℃)

I

SS

(uA)

Product Specification

Power Supply Supervisor + PWM SG6108

Operation description

Protection against over-voltage, short-circuit and fault conditions is mandatory for PC power supplies. Many commonly used protection circuits require large numbers of discrete components and comparators which occupy significant PCB space and add to assembly costs. This single chip controller IC provides complete protection, shunt regulation, and PWM control with comparatively few components. The SG6108 is an ideal controller IC for PC switching mode power supplies. The features and benefits of this device are listed on the first page.

Feature Notes

 Over voltage protection can be implemented without

any additional components. Over-voltage sense levels are 3.3V/5V/12V or 4.1V/6.1V/14.05V.

 The SG6108’s over current protection monitors the

3.3V, 5V, and the two 12V levels. The voltage difference across the external current shunt is used to provide accurate OCP.

 Over current and/or short circuit protection can also

be implemented by using over-power protection. To do this, the OPP pin must be connected to the current transformer (driver transformer).

 The power good signal is asserted to indicate that the

3.3V/5V/12V signals are above the under voltage threshold level. The PG pin goes high when the above condition is reached. A 2kΩ pull up resistor may be optionally connected to the 5V lead.

 VCC can be supplied from the 5V-standby.

Whenever the VCC voltage exceeds 7V the entire SG6108 will be shutdown and reset (except for the shunt regulator). No extra power supply is needed.

 Complete PWM control circuitry includes an error

amplifier for push-pull or half-bridge operation.

Supervisory Circuit Operation

The PC generates the remote ON/OFF logic (PSON) signal. When this is “Low” the power supply is “On”. When it is “High”, the power supply is switched off. The remote ON/OFF signal is supplied to the PSON input.

Application Guides

The application guide shows the key features of the SG6108 and illustrates how to use it in an ATX switching mode power supply (SMPS). The SG6108 is suitable for half-bridge, push-pull topologies. The PWM section of the SG6108 comprises a built-in 65kHz oscillator and high immunity circuits, which protect the system from noise interference and provide higher noise margins against improper PCB layout. The SG6108 has OVP, UVP, and OCP for the 3.3V and 5V signals, as wells as both 12V signals. NVP is used for negative voltage protection (–12V/–5V). UVAC (AC failure detection) is used to measure the AC line voltage.

AC Failure Detection

UVAC is connected to the secondary power transformer through a resistor divider. UVAC is used for detecting the AC line voltage. Whenever the UVAC voltage drops below 0.7V for a period of time such as 150usec, the PG (power good) signal will be pulled low to indicate an AC line power-down condition.

The voltage amplitude of the PWM switching signal in the secondary power transformer is proportional to the AC line voltage. The power-down warning threshold can be

controlled by adjusting the resistor-divider ratio. A small

capacitor must be connected between UVAC and ground

to filter the switching noise.

Over Power Protection (OPP)

OPP (over power protection) is used to detect over power and short-circuit conditions. Whenever the V

OPP

voltage

(p.7, Note-1) exceeds 2.3V for longer than 6msec the

SG6108 will pull PG low and lock off the power outputs.

+

UVAC

Vo

0.7V

R1

R2 C1

VS

Vin

Product Specification

Power Supply Supervisor + PWM SG6108

+

R2R1

2.1V

64uA

-12V

-5V

Vdd

OPP

OP2

OP1

R1 R2

R3

C1

Over Current Protection (OCP)

The SG6108 provides over current protection for the

3.3V, 5V and the two 12V rails. Whenever an OCP condition occurs at any of the voltage rails, PG will be low and PWM will be turned off. The internal OCP

comparators have a very small offset voltage (±5mV).

The sink currents of IS33, IS5, and IS12 are 8 times the current at the RI pin. The current at the RI pin is V

RI

/RI. Here is an example demonstrating how to set the over current protection threshold:

I

RI

= VRI/RI = 1.0V/75k = 13.3uA

If R1 = 1700Ω and R12 = 0.01Ω, then

OC P = 13.3uA x 8 x 1700 / 0.01 = 18 A

Negative Voltage Protection

NVP provides UVP (under voltage protection) for negative voltage outputs. An under-voltage condition indicates an overload at a negative voltage output. For example, the –12V output may drop to –10V during overload situations. The resistance of a resistor connected from NVP to the negative voltage output determines the protection threshold voltage. NVP outputs a 64uA constant current to the negative voltage output via this resistor. Whenever the NVP voltage exceeds 2.1V for longer than 7 msec the SG6108 will lock the power outputs off.

VNVP = 64 uA × (R1 + R2) – V-12V

The power outputs will be locked off when VNVP ≥

2.1V.

Product Specification

Power Supply Supervisor + PWM SG6108

REFERENCE CIRCUIT

Product Specification

Power Supply Supervisor + PWM SG6108

PACKAGE INFORMATION 20 PINS – DIP (D)

θ

e

B

E

A

A2

e

A1

L

b

b1

10

1

D

20

11

E1

Dimensions

Millimeters Inches

Symbol

Min. T

yp

.Max.Min.T

yp

.Max.

A 5.334 0.210

A1 0.381 0.015

A2 3.175 3.302 3.429 0.125 0.130 0.135

b

1.524 0.060

b

1 0.457 0.018

D 24.892 26.162 26.924 0.980 1.030 1.060

E 7.620 0.300

E1 6.223 6.350 6.477 0.245 0.250 0.255

e 2.540 0.100

L 2.921 3.302 3.810 0.115 0.130 0.150

eB 8.509 9.017 9.525 0.335 0.355 0.375 θ˚ 0° 7° 15° 0° 7° 15°

Product Specification

Power Supply Supervisor + PWM SG6108

SYSTEM GENERAL SG6108 Product Specification

Specifications and Main Features

Frequently Asked Questions

User Manual