KA3502_技术文档

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KA3502

PC SMPS Supervisory IC

Features

Descriptions

• Complete Housekeeping Circuit

• Few External Components

• Over Voltage Protection for 3.3V/5V/12V/Adj. Output

• Over Current Protection for 3.3V/5V/12V Output

• Open-Collector Output and Remote On/Off Function

• Remote On/Off Delay Time Control

The KA3502 is complete housekeeping circuitry for use in

the secondary side of SMPS(Switched Mode Power Supply).

It contains various functions, which are two Precision Volt-

age References, Over Voltage/Current Protection, Remote

On/Off Control, Power Good Signal Generator, Disable

Logic and etc.

• Precision Voltage Reference for Outputs, 5V/12V

• Uncommitment Precision Voltage Reference for +5Vs

• Power Good Signal Generator with Hysteresis

• Disable Logic of 3.3V, 5V, 12V for Complete Shutdown

20-DIP

1

Internal Block Diagram

V33

1

V5 V12

PWM FB1 VREF1 UV

VCC

5

2

3

6

15

14

11

Vcc

Adj

+

-

4

Ichg

R8

1k

R10

39k

R15

5.1k

COMP1

1.26V

9

Ion

R13

5.2V

R9

10k

PG

+

-

Vcc

COMP7

Q3

COMP9

1.3V

+

Vcc

Tsur

IS5

17

19

S

R

-

2V

↔

Vcc

Q

2.7V

Q1

Vcc

Q2

Vcc

REFERENCE1

+

-

+

-

+

-

+

50mV

COMP2

Vcc

COMP5

Vcc

COMP8

Vcc

R11

5.4k

12

2V

2.8V

IS33

IS12

20

18

+

FB2

+

R12

1.28V

↔1.24V

-

+

-

+

-

COMP3

Vcc

135mV

R14

2V↔0.7V

Ion+

Ioff

13

COMP6

REFERENCE2

+

-

VREF2

1.4V

-

+

COMP4

65mV

R7

7

8

16

10

Topr

GND

Trem

REM

Rev. 5.0

KA3502

Pin Assignments

#1

#20

V33

IS33

V5

IS5

V12

IS12

Adj

VCC

Tsur

GND

FB1

K

A

3

5

0

2

PWM

REM

Trem

PG

VREF1

VREF2

FB2

Topr

#10

UV

#11

NO

1

NAME

V33

FUNCTION

+3.3 V OUTPUT VOLTAGE

+5 V OUTPUT VOLTAGE

+12 V OUTPUT VOLTAGE

ADJUSTABLE OVP INPUT

SUPPLY VOLTAGE

NO

NAME

FUNCTION

PG INPUT for Det

11

12

13

14

15

16

17

18

19

20

UV

FB2

2

V5

FEEDBACK for REFERENCE 2

PRECISION REFERENCE

FEEDBACK for REFERENCE 1

GROUND

3

V12

VREF2

VREF1

FB1

4

Adj

5

VCC

PWM

REM

Trem

PG

6

REMOTE ON/OFF OUTPUT

REMOTE ON/OFF INPUT

REMOTE ON/OFF DELAY

POWER GOOD OUTPUT

PG DELAY

GND

Tsur

7

OCP DELAY

8

IS12

IS5

Current INPUT for +12V

Current INPUT for +5V

Current INPUT for +3.3V

9

10

Topr

IS33

2

KA3502

Pin Description

Pin Number Pin Name

Pin Function Descrition

+3.3 V Output Voltage of SMPS Secondary side

+5 V Output Voltage of SMPS Secondary side

+12 V Output Voltage of SMPS Secondary side

1

2

3

V33

V5

V12

Adjustable OVP Input. Its Threshold Voltage is 1.26 V. This pin can be used for

4

5

ADJ

another

protection signal.

VCC

Supply Voltage. Operating range is 15 V ~ 24 V. Vcc=18 V, Ta=25°C at test.

Remote On/Off Output. This signal controls the primary power switch (PWM IC)

through an Opto-coupler.

Maximum current rating is 30 mA. When PWM="Low", the main SMPS is operational

and If PWM="High", the main SMPS is turned-off.

6

7

8

PWM

REM

Trem

Remote On/Off Input. It is TTL operation and its threshold voltage is 1.4 V. Voltage at

this pin can reach normally 4.6 V, with absolutely maximum voltage, 5.25 V. If

REM="Low", PWM="Low". That means the main SMPS is operational. When REM

="High", then PWM="High" and the main SMPS is turned-off.

Remote On/Off delay. Ton/Toff=8 ms/24 ms (Typ.) with Ctrem=0.1uF. Its High/Low

threshold voltage is 2 V/0.7 V and the maximum voltage after full charging is about

2.8 V. So,

∆V (Chg.) = 2 V, ∆V (Dischg.) = 2.1 V Typ.

Power Good output signal. PG="High" means that the power is "Good" for operation

and PG="Low" means "Power Fail".

9

PG

PG Delay. Td=250 ms (Typ.) with Ctopr=2.2uF. The High/Low threshold voltage are

2 V/1.3 V and the voltage of PIN 10 is clamped at 5.2 V for Noise margin.

10

Topr

11

12

UV

Under-Voltage Detect Pin. Its threshold voltage is 1.26V ± 20mV Typ.

FB2

Feedback for Precision Reference2. Absolute min/max current rating is 1 mA/30 mA.

Precision Reference 2 input Voltage. This circuit equals to KA431 and it is designed

for an Auxiliary voltage,

+5 Vs. It is trimmed to ± 1.6%.

13

14

VREF2

VREF1

Precision Reference 1 Input Voltage. This circuit equals to KA431 and it is for

corrective output voltages of +5 V/+12 V. It's trimmed to ± 1.6%.

Feedback for Precision Reference1. Absolute min/max current rating is 2 mA/30 mA

15

16

17

FB1

GND

Tsur

because of

internal connection.

Ground

Timing pin for Over Current Protection blank-out time. Its threshold voltage is 2 V and

clamped at 2.7 V after full charging. Target of delay time is 20 ms~30 ms and it is

realized through external R & C.

Current Sense Input for +12V. This pin is connected to the Current Sensing resistor

or inductor. If the voltage drop of the resistor or inductor is larger than the fixed offset

voltage ( 65 mV Typ.), PWM becomes "High" after some delay and the main SMPS

is turned-off.

18

IS12

19

20

IS5

Current Sense Input for +5 V. The OCP Offset voltage for +5 V is 50 mV

Current Sense Input for +3.3 V. The OCP Offset voltage for +3.3 V is 135 mV

IS33

3

KA3502

Absolute Maximum Ratings

Parameter

Symbol

Vcc

Value

15 ~ 24

24

Unit

V

Supply Voltage

UV Input Voltage

Vuv

V

Input Maximum Voltage

Cathode Current for FB1, 2

PWM Maximum Current

PG Output Maximum Current

Power Dissipation

Vin (max)

Ik1, 2

Io (PWM)

Io (PG)

Pd

Vcc - 3

1 ~ 30

30

V

mA

W

30

1

Operating Temperature Range

Storage Temperature Range

Topr

0 ~ 70

-65 ~ 150

°C

Tstg

Temperature Characteristics

Parameter

Symbol

Value

Unit

Temperature Stability for Vref1, 2

(0°C ≤ Ta ≤ 70°C)

∆Vref1, 2

17

mV

4

KA3502

Electrical Characteristics (Vcc = 18V, Ta = 25°C)

Parameter

Symbol

Condition

Min.

Typ.

Max.

Unit

PROTECTION SECTION

Over Voltage Protection For 3.3 V

Over Voltage Protection For 5 V

Over Voltage Protection For 12 V

OVP Input Threshold Voltage for Adj

Comparator Offset Voltage for 3.3 V

Comparator Offset Voltage for 5 V

Comparator Offset Voltage for 12 V

Vovp33

Vovp5

Vovp12

Vadj

Pin 7 (REM)=0V

3.8

5.8

4.0

6.1

4.2

6.4

V

13.4

1.22

125.5

46.5

60.5

14.2

1.26

135

50

15.0

1.30

144.5

53.5

69.5

V

Vos33

Vos5

mV

Vos12

65

OCP Delay Comparator Input

Threshold Voltage

Vth (Tsur) Pin 7 (REM)=0V

1.9

-

2

2.1

4

V

Pin 17 (Tsur) Input Clamp Voltage

REMOTE ON/OFF SECTION

Remote On/off Input Threshold Vtg.

Remote On/off Input Open Voltage

Remote On/off Input Low Current

ON Delay Time

V17max

Pin 7 (REM)=0V

2.7

Vth

Vih

Iil

Pin 7 (REM): “L”→”H”

Pin 7 Open

1

4

-

1.8

5.25

-1.0

14

V

Pin 7 (REM)=0 V

REM: “L”→“H”, C=0.1 uF

Io=0.5 mA

0

-

mA

msec

V

Ton

Toff

4

8

24

-

OFF Delay Time

16

-

34

PWM Saturation Voltage

Vsat

1.3

(PWM)

PWM Leakage Current

REFERENCE 1 SECTION

Reference Input Voltage 1

Line Regulation 1

Ileak

Pin 6 (PWM)=20 V

IIk1=1 mA

-

0.01

1

uA

Vref1

2.46

2.50

1

2.54

V

mV/V

mV

mA

%

Vref1 (line) 15 V<Vcc<20 V

-

20

-

Current Stability 1

∆ Vref1

Isink1

Rint

Ik1=1 mA to 10 mA

5

Output Sinking Current Capability 1

-

15

-

25

± 15

Absolute Precision of Internal Three

Resistors

-

Matching Coefficient of Internal Three

Resistors

Rrate

-

± 1

-

%

Temperature Stability

Gain Bandwidth 1

∆ Vref1

Ta=0 to 70°C (Note 1)

-

13

1

17

-

mV

GBW1

GV=1 (Note 1)

MHz

5

KA3502

Electrical Characteristics (Continued)

Parameter

REFERENCE 2 SECTION

Reference Input Voltage 2

Line Regulation 2

Symbol

Condition

Min.

Typ.

Max.

Unit

Vref2

IIk2=1 mA

2.46

2.50

1

2.54

V

Vref2 (line) 15 V<Vcc<20 V

-

20

-

mV/V

mV

Current Stability 2

∆ Vref2

Isink2

Ik2 mA to 10 mA

-

5

Output Sinking Current Capability 2

Temperature Stability 2

15

-

25

13

1

mA

∆ Vref2

GBW2

Ta=0 to 70°C (Note 1)

GV=1 (Note 1)

17

-

mV

Gain Bandwidth 2

-

MHz

POWER GOOD SECTION

Detecting UV Voltage

Vuv

Vin (V5)

HY1

Pin 7 (REM)=0V

Pin 11 (UV): “L”↔“H”

Pin 10 (Topr): “L”↔ “H”

Vtopr (max) - Vth (L)

Pin 10 (Topr)=GND

Ctopr=2.2uF

1.22

4.1

20

0.2

1.8

2

1.26

4.3

40

1.30

4.5

80

-

V

Detecting V5 Voltage

Hysteresis Voltage 1

mV

V

Hysteresis Voltage 2

HY2

0.7

2.0

4

High Threshold Voltage of Comp 9

Noise margin of Vtopr

Vth (H)

∆ Vtopr

Ichg

2.2

-

V

Charging Current for PG Delay

Turn-On Delay Time for PG

UV Input Pull Down Resistor

PG Output Rising Time

-12

100

-

-18

250

20

-28

500

-

uA

msec

kohm

usec

nsec

V

Topr

Ruv

-

Tr

C=0.1nF (Note 1)

-

1

-

PG Output Falling Time

Tf

-

300

0.3

-

PG Output Saturation Voltage

PG Output Voltage at High Status

DISABLE SECTION

Vsat (PG) Isink=15 mA

-

0.4

5.25

Vpgh

Isource=100 uA

4.2

V

Disable Saturation Voltage for V33

Disable Saturation Voltage for V5

Disable Saturation Voltage for V12

TOTAL STANDBY CURRENT

Supply Current Of Vcc

Vdis33

Vdi5

REM=2 V, Isink=10 mA

-

0.2

0.4

V

Vdis12

Icc

Vcc=18 V, REM=2V

-

5

10

mA

Note:

1.These parameters, although guaranteed, but not 100% tested in production.

6

KA3502

Typical Characteristics

2.53

2.52

2.510

2.505

2.51

2.50

2.49

2.500

2.495

2.490

-25

0

25

50

75

100

0

5

10

15

20

25

30

Temp (Dgree)

1k (mA)

Figure 2. Vref1,2 Current Stability

Figure 1. Temperature Stability for Vref1,2

1.260

20

1.255

1.250

15

10

1.245

1.240

5

0

-25

0

25

50

75

100

1.10

1.15

1.20

1.25

1.30

1.35

Temp (Degree)

Vadj (V)

Figure 4. OVP Input Threshold Voltage for Adj

Figure 3. Bandgap Voltage (Vadj)

20

15

10

15

10

5

0

5.0

3.50

3.75

4.00

4.25

4.50

5.5

6.0

6.5

7.0

V33 (V)

V5 (V)

Figure 4. OCP Offiset Voltage for 3.3V

Figure 3. Over Voltage Protection for +3.3V

7

KA3502

Typical Characteristics (Continued)

20

15

10

5

20

15

10

5

Vos33=IS33-V33

0

12

0

13

14

15

16

110

120

130

140

150

V12 (V)

Vos33 (mV)

Figure 8. OCP Offiset Voltage for 3.3V

Figure 7. Over Voltage Protection for +12V

20

15

Vos=IS12-Vo12

Vos5=IS5-V5

15

10

5

10

5

0

55

0

60

65

70

75

40

45

50

55

60

V8 (V)

Vos5 (mV)

Figure 10. OCP Offiset Voltage for 12V

Figure 9. OCP Offiset Voltage for 5V

20

15

10

15

10

5

0

0.0

0.5

1.0

1.5

2.0

0.0

0.5

1.0

1.5

2.0

2.5

Vth (V)

V8 (V)

Figure 12. ON/OFF Delay Threshold Voltage

Figure 11. Remotr On/Off Input Threshold

8

KA3502

Typical Characteristics (Continued)

25

20

6

5

4

15

10

3

2

5

0

1

0

5

10

15

20

1.20

1.22

1.24

1.26

1.28

1.30

Isink (mA)

Vuv (V)

Figure 14. Detecting UV Voltage

Figure 13. PWM Saturation Voltage

5

4

5

4

3

2

1

0

2

1

0

0.5

5.0

4.8

4.6

4.4

4.2

4.0

1.0

1.5

2.0

2.5

V5 (V)

V10 (V)

Figure 15. Detecting V5 Voltage for PG

Figure 16. High/low Threshold Voltage of Comp9

0.4

0.3

0.2

0.3

0.2

0.1

0.0

0.1

0.0

0

5

10

15

20

0

5

10

15

20

25

Isink (mA)

Figure 17. PG Saturating Voltage

Figure 18. Disable Saturation Voltage

9

KA3502

Typical Characteristics (Continued)

10

8

20

15

10

PWM

6

4

REM

5

0

2

0

14

16

18

20

22

24

0

20

40

60

80

100

Vcc (V)

Time (msec)

Figure 19. Supply Current of Vcc

Figure 20.

6

PG

5

4

3

UV

2

1

0

0.0

0.2

0.4

0.6

0.8

1.0

Time (sec)

Figure 21. PG Delay

10

KA3502

Mechanical Dimensions

Package

Dimensions in millimeters

20-DIP

11

KA3502

Ordering Information

Product Number

Package

20-DIP

Operating Temperature

KA3502

0°C ~ 70°C

12

KA3502

13

KA3502

DISCLAIMER

FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY

PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY

LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER

DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS.

LIFE SUPPORT POLICY

FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES

OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR

INTERNATIONAL. As used herein:

1. Life support devices or systems are devices or systems

which, (a) are intended for surgical implant into the body,

or (b) support or sustain life, and (c) whose failure to

perform when properly used in accordance with

instructions for use provided in the labeling, can be

reasonably expected to result in a significant injury of the

user.

2. A critical component in any component of a life support

device or system whose failure to perform can be

reasonably expected to cause the failure of the life support

device or system, or to affect its safety or effectiveness.

www.fairchildsemi.com

9/25/00 0.0m 001

Stock#DSxxxxxxxx

2000 Fairchild Semiconductor International


型号：	KA3502
厂家：	FAIRCHILD SEMICONDUCTOR
描述：	PC SMPS Supervisory IC PC开关电源监控IC 开关监控 PC
文件：	总14页 (文件大小：91K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

KA3502 [FAIRCHILD]

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