MAX1846EUB+ Datasheet MAX1846EUB+, MAX1847EEE+, MAX1846EUB+T | P4-P6

MAX1846/MAX1847

High-Efficiency, Current-Mode,

Inverting PWM Controller

4 _______________________________________________________________________________________

ELECTRICAL CHARACTERISTICS

(V

SHDN

= V

IN

= +12V, SYNC = GND, PGND = GND, R

FREQ

= 147kΩ ±1%, C

VL

= 0.47µF, C

REF

= 0.1µF, T

A

= -40°C to +85°C,

unless otherwise noted.) (Note 3)

PARAMETER CONDITIONS MIN MAX UNITS

PWM CONTROLLER

Operating Input Voltage Range 3.0 16.5 V

V

IN

rising 2.95

UVLO Threshold

V

IN

falling 2.6

V

FB Threshold No load -20 +20 mV

FB Input Current V

FB

= -0.1V -50 +50 nA

Load Regulation

C

COMP

= 0.068µF, V

OUT

= -48V,

I

OUT

= 20mA to 200mA (Note 1)

-2 0 %

Current Limit Threshold 85 115 mV

CS Input Current CS = GND 20 µA

Supply Current V

FB

= -0.1V, V

IN

= +3.0V to +16.5V 1.2 mA

Shutdown Supply Current SHDN = GND, V

IN

= +3.0V to +16.5V 25 µA

REFERENCE AND VL REGULATOR

REF Output Voltage I

REF

= 50µA 1.225 1.275 V

REF Load Regulation I

REF

= 0 to 500µA -15 mV

VL Output Voltage I

VL

= 100µA 3.85 4.65 V

VL Load Regulation I

VL

= 0.1mA to 2.0mA -60 mV

OSCILLATOR

R

FREQ

= 500kΩ ±1% 84 116

Oscillator Frequency

R

FREQ

= 147kΩ ±1% 255 345

kHz

R

FREQ

= 500kΩ ±1% 93 98

Maximum Duty Cycle

R

FREQ

= 147kΩ ±1% 84 93

%

SYNC Input Signal Duty-Cycle

Range

7 93 %

Minimum SYNC Input Logic Low

Pulse Width

200 ns

SYNC Input Rise/Fall Time (Note 2) 200 ns

SYNC Input Frequency Range 100 550 kHz

DIGITAL INPUTS

POL, SYNC, SHDN Input High

Voltage

2.0 V

POL, SYNC, SHDN Input Low

Voltage

0.45 V

MAX1846/MAX1847

High-Efficiency, Current-Mode,

Inverting PWM Controller

_______________________________________________________________________________________

5

100

0

1 10 100 1000 10,000

EFFICIENCY vs. LOAD CURRENT

20

MAX1846/7 toc01

LOAD CURRENT (mA)

EFFICIENCY (%)

40

60

80

70

50

30

10

90

V

IN

= 5V

V

IN

= 16.5V

V

OUT

= -5V

APPLICATION CIRCUIT A

100

0

1 10 100 1000 10,000

EFFICIENCY vs. LOAD CURRENT

20

MAX1846/7 toc02

LOAD CURRENT (mA)

EFFICIENCY (%)

40

60

80

70

50

30

10

90

V

IN

= 5V

V

IN

= 3.3V

V

OUT

= -12V

APPLICATION CIRCUIT B

V

IN

= 3V

90

0

1 100010010

EFFICIENCY vs. LOAD CURRENT

30

10

70

50

100

40

20

80

60

MAX1846/7 toc03

LOAD CURRENT (mA)

EFFICIENCY (%)

V

IN

= 12V

V

IN

= 16.5V

APPLICATION CIRCUIT C

V

OUT

= -48V

-12.10

-12.04

-12.06

-12.08

-12.02

-12.00

-11.98

-11.96

-11.94

-11.92

-11.90

0 200100 300 400 500 600

OUTPUT VOLTAGE LOAD REGULATION

MAX1846/7 toc04

LOAD CURRENT (mA)

OUTPUT VOLTAGE (V)

APPLICATION CIRCUIT B V

IN

= 5V

0

0.4

0.2

0.8

0.6

1.0

1.2

1.4

1.6

0462 8 10 12 14 16

SUPPLY CURRENT

vs. SUPPLY VOLTAGE

MAX1846/7 toc05

V

IN

(V)

I

IN

(mA)

V

FB

= -0.1V

1.238

1.246

1.242

1.254

1.250

1.258

1.262

-40 20 40-20 0 60 80 100

REFERENCE VOLTAGE

vs. TEMPERATURE

MAX1846/7 toc06

TEMPERATURE (°C)

V

REF

(V)

Typical Operating Characteristics

(Circuit references are from Table 1 in the

Main Application Circuits

section, C

VL

= 0.47µF, C

RE

F

= 0.1µF, T

A

= +25°C, unless otherwise

noted.)

ELECTRICAL CHARACTERISTICS (continued)

(V

SHDN

= V

IN

= +12V, SYNC = GND, PGND = GND, R

FREQ

= 147kΩ ±1%, C

VL

= 0.47µF, C

REF

= 0.1µF, T

A

= -40°C to +85°C,

unless otherwise noted.) (Note 3)

PARAMETER CONDITIONS MIN MAX UNITS

POL, SYNC Input Current POL, SYNC = GND or VL 40 µA

V

SHDN

= +5V or GND -12 0

SHDN Input Current

V

SHDN

= +16.5V 6

µA

EXT OUTPUT

EXT high or low, I

EXT

= 100mA, V

IN

= +5V 7.5

EXT On-Resistance

EXT high or low, I

EXT

= 100mA, V

IN

= +3V 12

Ω

Note 3: Parameters to -40°C are guaranteed by design and characterization.

MAX1846/MAX1847

High-Efficiency, Current-Mode,

Inverting PWM Controller

6 _______________________________________________________________________________________

SHUTDOWN SUPPLY CURRENT

vs. TEMPERATURE

MAX1846/7 toc10

0

2

6

4

12

14

10

8

16

SHUTDOWN SUPPLY CURRENT (µA)

-40 0 20-20

40

60 80 100

TEMPERATURE (°C)

V

IN

= 10V

V

IN

= 16.5V

V

IN

= 3V

0

4

2

8

6

12

10

14

-40 0 20-20 40 60 80 100

OPERATING CURRENT

vs. TEMPERATURE

MAX1846/7 toc11

TEMPERATURE (

°

C)

OPERATING CURRENT (mA)

A

B

C

A: V

IN

= 3V, V

OUT

= -12V

B: V

IN

= 5V, V

OUT

= -5V

C: V

IN

= 16.5V, V

OUT

= -5V

APPLICATION CIRCUIT A

0

100

300

200

400

500

0200100 300 400 500 600

SWITCHING FREQUENCY

vs. R

FREQ

MAX1846/7 toc12

R

FREQ

(k

Ω

)

f

OSC

(kHz)

SWITCHING FREQUENCY

vs. TEMPERATURE

MAX1846/7 toc13

294

295

297

296

300

301

299

298

302

FREQUENCY (kHz)

-40 0 20-20

40

60 80 100

TEMPERATURE (°C)

R

FREQ

= 147kΩ ±1%

0

40

20

60

120

140

100

80

160

0 2000 4000 6000 8000 10,000

EXT RISE/FALL TIME

vs. CAPACITANCE

MAX1846/7 toc14

CAPACITANCE (pF)

TIME (ns)

RISE TIME

FALL TIME

V

IN

= 12V

I

L

0

5V/div

1A/div

5V/div

V

OUT

EXITING SHUTDOWN

MAX1846/7 toc15

APPLICATION CIRCUIT B

1ms/div

SHDN

Typical Operating Characteristics (continued)

(Circuit references are from Table 1 in the

Main Application Circuits

section, C

VL

= 0.47µF, C

RE

F

= 0.1µF, T

A

= +25°C, unless otherwise

noted.)

1.240

1.245

1.255

1.250

1.260

0 100 200 300 400 500

REFERENCE LOAD REGULATION

MAX1846/7 toc07

I

REF

(

µ

A)

V

REF

(V)

4.100

4.180

4.140

4.260

4.220

4.300

4.340

-40 20 40-20 0 60 80 100

VL VOLTAGE

vs. TEMPERATURE

MAX1846/7 toc08

TEMPERATURE (

°

C)

VL (V)

I

VL

= 0

4.22

4.23

4.24

4.25

4.26

4.27

0 0.8 1.00.4 0.60.2 1.2 1.4 1.6 1.8 2.0

VL LOAD REGULATION

MAX1846/7 toc09

I

VL

(mA)

VL (V)

MAX1846EUB+

MAX1846EUB+

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