beautypg.com

Electrical characteristics – Rainbow Electronics MAX8742 User Manual

Page 5

background image

MAX8741/

M
AX8742

500kHz Multi-Output Power-Supply Controllers

with High Impedance in Shutdown

_______________________________________________________________________________________

5

ELECTRICAL CHARACTERISTICS

(V+ = 15V, both PWMs on, SYNC = V

L

, V

L

load = 0, REF load = 0, SKIP = 0,

T

A

= -40°C to +85°C

, unless otherwise noted.) (Note 6)

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

MAIN SMPS CONTROLLERS

Input Voltage Range

4.2

30.0

V

3V Output Voltage in Adjustable Mode

V+ = 4.2V to 30V, CSH3 - CSL3 = 0,
CSL3 connected to FB3

2.42

2.58

V

3V Output Voltage in Fixed Mode

V+ = 4.2V to 30V, 0 < CSH3 - CSL3
< 80mV, FB3 = 0

3.20

3.47

V

5V Output Voltage in Adjustable Mode

V+ = 4.2V to 30V, CSH5 - CSL5 = 0,
CSL5 connected to FB5

2.42

2.58

V

5V Output Voltage in Fixed Mode

V+ = 5.3V to 30V, 0 < CSH5 - CSL5
< 80mV, FB5 = 0

4.85

5.25

V

Output Voltage Adjust Range

Either SMPS

REF

5.5

V

Adjustable-Mode Threshold Voltage

Dual-mode comparator

0.5

1.1

V

CSH3 - CSL3 or CSH5 - CSL5

80

120

Current-Limit Threshold

SKIP = V

L

or V

DD

< 13V or SECFB < 2.44V

-50

-150

mV

SYNC = V

L

450

550

Oscillator Frequency

SYNC = 0

283

383

kHz

SYNC = V

L

95

Maximum Duty Factor

SYNC = 0 (Note 2)

97

%

SYNC Input Frequency Range

400

583

kHz

FLYBACK CONTROLLER

V

DD

Regulation Threshold

Falling edge (MAX8742)

13

14

V

SECFB Regulation Threshold

Falling edge (MAX8741)

2.44

2.60

V

V

DD

Shunt Threshold

Rising edge, hysteresis = 1% (MAX8742)

18

20

V

V

DD

Shunt Sink Current

V

DD

= 20V (MAX8742)

10

mA

12V LINEAR REGULATOR

(MAX8742)

12OUT Output Voltage

13V < V

DD

< 18V, 0mA < I

LOAD

< 100mA

11.65

12.50

V

Quiescent V

DD

Current

V

DD

= 18V, run mode, no 12OUT load

100

µA

INTERNAL REGULATOR AND REFERENCE

V

L

Output Voltage

SHDN = V+, RUN/ON3 = TIME/ON5 = 0,
5.4V < V+ < 30V, 0 < I

LOAD

< 50mA

4.7

5.1

V

V

L

Undervoltage-Lockout Fault Threshold

Falling edge, hysteresis = 1%

3.5

3.7

V

V

L

Switchover Threshold

Rising edge of CSL5, hysteresis = 1%

4.2

4.7

V

REF Output Voltage

No external load (Note 4)

2.45

2.55

V

0 < I

LOAD

< 50µA

12.5

REF Load Regulation

0 < I

LOAD

< 5mA

100.0

mV

REF Sink Current

10

µA

REF Fault-Lockout Voltage

Falling edge

1.8

2.4

V

V+ Operating Supply Current

V

L

switched over to CSL5, 5V SMPS on

50

µA