MAXIM MAX5019, MAX5020 User Manual

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General Description

The MAX5019/MAX5020 integrate all the building
blocks necessary for implementing DC-DC fixed-fre­quency power supplies. Either primary- or secondary­side regulation may be used to implement isolated or
nonisolated power supplies. These devices are current­mode controllers with an integrated high-voltage start­up circuit suitable for telecom/industrial voltage range
power supplies. Current-mode control with leading­edge blanking simplifies control-loop design and inter­nal ramp compensation circuitry stabilizes the current
loop when operating at duty cycles above 50%
(MAX5019). The MAX5019 allows 85% operating duty
cycle and can be used to implement flyback converters
whereas the MAX5020 limits the operating duty cycle to
less than 50% and can be used in single-ended for­ward converters. A high-voltage startup circuit allows
these devices to draw power directly from the 18V to
110V input supply during startup. The switching fre­quency is internally trimmed to 275kHz ±10%, thus
reducing magnetics and filter component costs.

The MAX5019/MAX5020 are available in 8-pin SO
packages.

Warning: The MAX5019/MAX5020 operate with high
voltages. Exercise caution.

Applications

Telecom Power Supplies

Industrial Power Supplies

Networking Power Supplies

Isolated Power Supplies

Features

♦ Wide Input Range: (18V to 110V) or (13V to 36V)

♦ Isolated (without optocoupler) or Nonisolated

Power Supply

♦ Current-Mode Control

♦ Leading-Edge Blanking

♦ Internally Trimmed 275kHz ±10% Oscillator

♦ Low External Component Count

♦ Soft-Start

♦ High-Voltage Startup Circuit

♦ Pulse-by-Pulse Current Limiting

♦ Thermal Shutdown

♦ SO-8 Package

MAX5019/MAX5020

Current-Mode PWM Controllers with Integrated

Startup Circuit

________________________________________________________________ Maxim Integrated Products 1

Pin Configuration

Ordering Information

NDRV

V

IN

V

OUT

V

DD

V

CC

CS

FB

MAX5020

V+

SS_SHDN

GND

Typical Operating Circuit

19-2115; Rev 0; 7/01

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

*See Selector Guide at end of data sheet.

PART TEMP. RANGE PIN-PACKAGE

MAX5019CSA* 0°C to +70°C8-SO

MAX5019ESA* -40°C to +85°C8-SO
MAX5020CSA* 0°C to +70°C8-SO
MAX5020ESA* -40°C to +85°C8-SO

TOP VIEW

V+

1

2

DD

FB

SS_SHDN

3

4

MAX5019/

MAX5020

8-SO

87V

6

5

CC

NDRVV

GND

CS

MAX5019/MAX5020

Current-Mode PWM Controllers with Integrated
Startup Circuit

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VDD= 13V, a 10µF capacitor connects VCCto GND, VCS= 0, V+ = 48V, 0.1µF capacitor connected from SS_SHDN to GND, NDRV
= open circuit, V

FB

= 3V, TA= -40°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.)

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.

V+ to GND……………………………………...……-0.3V to +120V
V

DD

to GND.………………………………….……….-0.3V to +40V

V

CC

to GND.………………….……………………-0.3V to +12.5V

FB, NDRV, SS_SHDN, CS to GND .……-0.3V to V

CC

+ 0.3V

V

DD

and VCCCurrent …………………...…………………..20mA
NDRV Current Continuous...………………………………….25mA
NDRV Current for Less than 1µs..………….…………….……±1A

Continuous Power Dissipation (T

A

= +70°C)

8-Pin SO (derate 5.88mW/°C above +70°C) .………....471mW

Operating Temperature Range…………..……...-40°C to +85°C
Storage Temperature Range……………..…….-65°C to +150°C
Lead Temperature (soldering, 10s) ………………………+300°C

)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

SUPPLY CURRENT

V+ Supply Current

V+ Supply Current After Startup V+ = 110V, VDD = 13V, FB = GND 14 µA

V

S up p l y C ur r ent

D D

V+ Shutdown Current V

VDD Shutdown Current V

PREREGULATOR/STARTUP

V+ Input Voltage 18 110 V

V

Supply Voltage 13 36 V

DD

INTERNAL REGULATORS (VCC)

VCC Output Voltage

VCC Undervoltage Lockout V

OUTPUT DRIVER

Peak Source Current VCC = 11V (externally forced) 570 mA

Peak Sink Current VCC = 11V (externally forced) 1000 mA

NRDV High-Side Driver
Resistance

I

V+(NS)

I

V+(S)

I

VDD(NS

I

VDD(S)

CC_UVLOVCC

R

OH

VDD = 0, V+ = 110V, driver not switching 0.8 1.6

V+ = 110V, VDD = 0, FB = GND,
driver switching

VDD = 36V, driver not switching 0.9 1.6

VDD = 36V, driver switching, FB = GND 2.1 3.0

SS_SHDN

SS_SHDN

Powered from V+, ICC = 7.5mA, VDD = 0 7.5 9.8 12.0 V

Powered from V

VCC = 11V, externally forced,
NDRV sourcing 50mA

= 0, V+ = 110V 180 290 µA

= 0 4 20 µ A

, ICC = 7.5mA 9.0 10.0 11.0 V

DD

falling 6.6 V

1.6 3.0

412Ω

mA

mA

NDRV Low-Side Driver
Resistance

ERROR AMPLIFIER

FB Input Resistance R

FB Input Bias Current I

Error Amplifier Gain (Inverting) A

Closed-Loop 3dB Bandwidth 200 kHz

FB Input Voltage Range 23V

R

OL

IN

FB

VCL

VCC = 11V, externally forced,
NDRV sinking 50mA

V

FB = VSS_SHDN

1.6 4 Ω

50 kΩ
±1 µA

-20 V/V

MAX5019/MAX5020

Current-Mode PWM Controllers with Integrated

Startup Circuit

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(VDD= 13V, a 10µF capacitor connects VCCto GND, VCS= 0, V+ = 48V, 0.1µF capacitor connected from SS_SHDN to GND, NDRV
= open circuit, V

FB

= 3V, TA= -40°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.)

Typical Operating Characteristics

(V+ = 48V, VDD= 13V, CS = GND, NRDV is open circuit, TA= +25°C, unless otherwise noted.)

0.999

1.000

1.001

1.002

1.003

-40 0-20 20 40 60 80

V

SS_SHDN

vs. TEMPERATURE

(AT THE END OF SOFT-START)

MAX5019 toc01

TEMPERATURE (°C)

VFB = 4V

V

SS_SHDN

(V) (NORMALIZED TO V

REF

= 2.4V)

273

274

276

275

277

278

-40 0-20 20 40 60 80

NDRV FREQUENCY

vs. TEMPERATURE

MAX5019 toc02

TEMPERATURE (°C)

NDRV FREQUENCY (kHz)

FB = GND

80.4

80.6

80.5

80.8

80.7

80.9

81.0

-40 20 40-20 0 60 80

MAX5019

MAXIMUM DUTY CYCLE

vs. TEMPERATURE

MAX5019 toc03

TEMPERATURE (°C)

MAXIMUM DUTY CYCLE (%)

FB = GND

SLOPE COMPENSATION

Slope Compensation
(MAX5019 only)

THERMAL SHUTDOWN

Thermal Shutdown Temperature 150 °C
Thermal Hysteresis 25 °C

CURRENT LIMIT

CS Threshold Voltage V
CS Input Bias Current 0 ≤ VCS ≤ 2V, FB = GND -1 1 µA

Current Limit Comparator
Propagation Delay

CS Blanking Time FB = GND, only PWM comparator is blanked 70 ns

OSCILLATOR

Clock Frequency Range FB = GND 247 275 302 kHz

Max Duty Cycle

SOFT-START

SS Source Current I

SS Sink Current 1.0 mA

Steady State Reference Voltage
at SS_SHDN

Shutdown Threshold

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

V

SCOMP

ILIM

FB = GND 419 465 510 mV

26 mV/µs

50mV overdrive on CS, FB = GND 180 ns

MAX5019, FB = GND 75 85

MAX5020, FB = GND 44 50

SSO

V

_SHDN No external load 2.331 2.420 2.500 V

SS

V

SS_SHDN

V

SS_SHDN

V

SS_SHDN

= 0 2.0 4.5 6.5 µA

falling 0.25 0.37 0.41

rising 0.53 0.59 0.65

%

V

MAX5019/MAX5020

Current-Mode PWM Controllers with Integrated
Startup Circuit

4 _______________________________________________________________________________________

Typical Operating Characteristics (continued)

(V+ = 48V, VDD= 13V, CS = GND, NRDV is open circuit, TA= +25°C, unless otherwise noted.)

MAX5020

MAXIMUM DUTY CYCLE

vs. TEMPERATURE

48.0

47.8

47.6

47.4

47.2

MAXIMUM DUTY CYCLE (%)

47.0

46.8

-40 20 40-20 0 60 80

FB = GND

TEMPERATURE (°C)

MAX5019 toc04

V+ SUPPLY CURRENT

vs. TEMPERATURE

1.64

1.63

1.62

1.61

1.60

1.59

1.58

V+ SUPPLY CURRENT (mA)

1.57

1.56

1.55

-40 0 20-20

FB = VDD = GND

TEMPERATURE (°C)

MAX5019 toc05

SOFT-START SOURCE CURRENT (µA)

60 80

40

SOFT-START SOURCE CURRENT

vs. TEMPERATURE

4.50

4.49

4.48

4.47

4.46

4.45

4.44

4.43

4.42

4.41

4.40

-40 -20 0 20 40 60 80

VDD = FB = SS_SHDN = GND

V+ = 110V

TEMPERATURE (°C)

MAX5019 toc06

V+ INPUT CURRENT vs.

TEMPERATURE (AFTER STARTUP)

13.80

13.75

V+ = 110V, VDD = 13V, FB = GND

-40 0-20 20 40 60 80
TEMPERATURE (°C)

V+ INPUT CURRENT (µA)

13.70

13.65

13.60

13.55

13.50

NDRV RESISTANCE
vs. TEMPERATURE

5.0

4.5

NDRV RESISTANCE (Ω)

4.0

3.5

3.0

2.5

2.0

1.5

1.0

-40 0 20-20

HIGH-SIDE DRIVER

LOW-SIDE DRIVER

TEMPERATURE (°C)

MAX5019 toc07

V+ SHUTDOWN CURRENT

vs. TEMPERATURE

182.5

V+ SHUTDOWN CURRENT (µA)

182.0

181.5

181.0

180.5

180.0

179.5

179.0

V+ = 110V, FB = SS_SHDN = GND

-40 -20 0 20 40 60 80
TEMPERATURE (°C)

0.488

MAX5019 toc08

0.487

0.486

0.485

CS THRESHOLD VOLTAGE (V)

0.484

0.483

CS THRESHOLD VOLTAGE

vs. TEMPERATURE

MAX5019 toc09

FB = GND

-40 0-20 20 40 60 80
TEMPERATURE (°C)

CURRENT-LIMIT DELAY

V

vs. TEMPERATURE

MAX5019 toc11

2.410

2.408

(V)

2.406

SS_SHDN

V

2.404

2.402

2.400
010155 2025303540

210

208

MAX5019 toc10

206

FB = GND, 100mV OVERDRIVE ON CS

204

202

200

198

196

194

CURRENT-LIMIT DELAY (ns)

192

190

60 80

40

188

-40 -20 0 20 40 60 80

TEMPERATURE (°C)

SS_SHDN

VDD (V)

vs. V

DD

MAX5019 toc12

_______________________________________________________________________________________ 5

MAX5019/MAX5020

Current-Mode PWM Controllers with Integrated

Startup Circuit

Typical Operating Characteristics (continued)

(V+ = 48V, VDD= 13V, CS = GND, NRDV is open circuit, TA= +25°C, unless otherwise noted.)

267.0

268.0

267.5

269.0

268.5

269.5

270.0

270.5

271.0

010155 2025303540

NDRV FREQUENCY vs. V

DD

MAX5019 toc13

VDD (V)

NDRV FREQUENCY (kHz)

FB = GND

47.0

47.2

47.1

47.4

47.3

47.6

47.5

47.7

47.9

47.8

48.0

010155 2025303540

MAX5020

MAXIMUM DUTY CYCLE vs. V

DD

MAX5019 toc14

VDD (V)

MAXIMUM DUTY CYCLE (%)

VFB = 4V, CS = GND

DEVICE POWERED
FROM V+

DEVICE POWERED
FROM V

DD

9.5

9.6

9.8

9.7

10.0

10.1

9.9

10.2

010155 2025303540

VCC vs. V

DD

MAX5019 toc15

VDD (V)

V

CC

(V)

DEVICE POWERED FROM V

DD

DEVICE POWERED
FROM V+

FB = GND

1.51

1.53

1.52

1.56

1.55

1.54

1.59

1.58

1.57

1.60

04020 60 80 100

V+ SUPPLY CURRENT vs.

V+ VOLTAGE

MAX5019 toc16

V+ VOLTAGE (V)

V+ SUPPLY CURRENT (mA)

VFB = VDD = GND

0

2

14

6

4

8

10

12

16

0403010 20 50 60 70 80 90 110

V+ SUPPLY CURRENT vs. V+ VOLTAGE

(AFTER STARTUP)

MAX5019 toc17

V+ VOLTAGE (V)

V+ LEAKAGE CURRENT (µA)

100

VDD = 13V, FB = GND

9.0

9.4

9.2

9.8

9.6

10.2

10.0

10.4

VCC VOLTAGE vs. VCC CURRENT

MAX5019 toc18

VCC CURRENT (mA)

V

CC

VOLTAGE (V)

0 5.0 10.0 15.0 20.0

V+ = 110V, VFB = 4V

VDD = 36V

VDD = 13V

9.0

9.3

9.2

9.1

9.4

9.5

9.6

9.7

9.8

9.9

10.0

0 5.0 10.0 15.0 20.0

VCC VOLTAGE vs. VCC CURRENT

MAX5019 toc19

VCC CURRENT (mA)

V

CC

VOLTAGE (V)

VDD = GND, VFB = 4V

V+ = 110V

V+ = 90V

V+ = 72V

V+ = 48V

V+ = 36V

V+ = 24V