Rainbow Electronics MAX5974D User Manual

19-5331; Rev 1; 9/10

Active-Clamped, Spread-Spectrum,

Current-Mode PWM Controllers

General Description

The MAX5974_ provide control for wide-input-voltage,
active-clamped, current-mode PWM, forward converters
in Power-over-Ethernet (PoE) powered device (PD) appli­cations. The MAX5974A/MAX5974C are well-suited for
universal or telecom input range, while the MAX5974B/
MAX5974D also accommodate low input voltage down
to 10.5V.

The devices include several features to enhance supply
efficiency. The AUX driver recycles magnetizing cur­rent instead of wasting it in a dissipative clamp circuit.
Programmable dead time between the AUX and main
driver allows for zero-voltage switching (ZVS). Under light­load conditions, the devices reduce the switching fre­quency (frequency foldback) to reduce switching losses.

The MAX5974A/MAX5974B feature unique circuitry to
achieve output regulation without using an optocoupler,
while the MAX5974C/MAX5974D utilize the traditional
optocoupler feedback method. An internal error amplifier
with a 1% reference is very useful in nonisolated design,
eliminating the need for an external shunt regulator.

The devices feature a unique feed-forward maximum
duty-cycle clamp that makes the maximum clamp volt­age during transient conditions independent of the line
voltage, allowing the use of a power MOSFET with lower
breakdown voltage. The programmable frequency dither­ing feature provides low-EMI, spread-spectrum operation.

The MAX5974_ are available in 16-pin TQFN-EP pack­ages and are rated for operation over the -40°C to +85°C
temperature range.

Ordering Information

Features

S Peak Current-Mode Control, Active-Clamped

Forward PWM Controller

Regulation Without Optocoupler (MAX5974A/

S

MAX5974B)

Internal 1% Error Amplifier

S

100kHz to 600kHz Programmable Q8% Switching

S

Frequency, Synchronization Up to 1.2MHz

Programmable Frequency Dithering for Low-EMI,

S

Spread-Spectrum Operation

Programmable Dead Time, PWM Soft-Start,

S

Current Slope Compensation

Programmable Feed-Forward Maximum Duty-

S

Cycle Clamp, 80% Maximum Limit

Frequency Foldback for High-Efficiency Light-

S

Load Operation

Internal Bootstrap UVLO with Large Hysteresis

S

100µA (typ) Startup Supply Current

S

Fast Cycle-by-Cycle Peak Current-Limit, 35ns

S

Typical Propagation Delay

115ns Current-Sense Internal Leading-Edge

S

Blanking

Output Short-Circuit Protection with Hiccup Mode

S

Reverse Current Limit to Prevent Transformer

S

Saturation Due to Reverse Current

S

3mm x 3mm, Lead-Free, 16-Pin TQFN-EP

Applications

PoE IEEE® 802.3af/at Powered Devices
High-Power PD (Beyond the 802.3af/at Standard)
Active-Clamped Forward DC-DC Converters
IP Phones
Wireless Access Nodes
Security Cameras

MAX5974A/MAX5974B/MAX5974C/MAX5974D

PART TOP MARK PIN-PACKAGE UVLO THRESHOLD (V) FEEDBACK MODE

MAX5974AETE+ +AHY 16 TQFN-EP* 20 Sample/Hold
MAX5974BETE+ +AHZ 16 TQFN-EP* 10 Sample/Hold
MAX5974CETE+ +AIA 16 TQFN-EP* 20 Continuously Connected
MAX5974DETE+ +AIB 16 TQFN-EP* 10 Continuously Connected

Note: All devices are specified over the -40°C to +85°C operating temperature range.

+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.

IEEE is a registered service mark of the Institute of Electrical and Electronics Engineers, Inc.

_______________________________________________________________ Maxim Integrated Products 1

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

Active-Clamped, Spread-Spectrum,
Current-Mode PWM Controllers

ABSOLUTE MAXIMUM RATINGS

IN to GND ..............................................................-0.3V to +26V

EN, NDRV, AUXDRV to GND .....................-0.3V to (V

RT, DT, FFB, COMP, SS, DCLMP, DITHER/SYNC

to GND .................................................................-0.3V to +6V

FB to GND (MAX5974A/MAX5974B only) ..................-6V to +6V

FB to GND (MAX5974C/MAX5974D only) ..............-0.3V to +6V

CS, CSSC to GND ...................................................-0.8V to +6V

PGND to GND ......................................................-0.3V to +0.3V

Maximum Input/Output Current (continuous)

NDRV, AUXDRV ............................................................100mA

NDRV, AUXDRV (pulsed for less than 100ns) .................. Q1A

Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-

layer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial.

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.

+ 0.3V)

IN

ELECTRICAL CHARACTERISTICS

(VIN = 12V (for MAX5974A/MAX5974C, bring VIN up to 21V for startup), V
V

, VEN = +2V, NDRV = AUXDRV = SS = COMP = unconnected, RRT = 34.8kI, RDT = 25kI, CIN = 1FF, TA = -40NC to +85NC,

GND

unless otherwise noted. Typical values are at T

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

UNDERVOLTAGE LOCKOUT/STARTUP (IN)

Bootstrap UVLO Wakeup Level V

Bootstrap UVLO Shutdown
Level

IN Supply Current in
Undervoltage Lockout

IN Supply Current After Startup I

ENABLE (EN)

Enable Threshold

Input Current I

MAX5974A/MAX5974B/MAX5974C/MAX5974D

OSCILLATOR (RT)

RT Bias Voltage V

NDRV Switching Frequency
Range

NDRV Switching Frequency
Accuracy

Maximum Duty Cycle D

V

I

= +25NC.) (Note 2)

A

INUVR

INUVF

START

C

V

ENR

V

ENF

EN

RT

f

SW

MAX

VIN rising

VIN falling 6.65 7 7.35 V

VIN = +18V (for MAX5974A/
MAX5974C);
V

= +9V (for MAX5974B/MAX5974D),

IN

when in bootstrap UVLO

VIN = +12V 1.8 3 mA

VEN rising 1.17 1.215 1.26
VEN falling 1.09 1.14 1.19
1

fSW = 250kHz 79 80 82 %

Continuous Power Dissipation (T

16-Pin TQFN (derate 20.8mW/NC above +70NC) .......1666mW

Junction-to-Case Thermal Resistance (B

16-Pin TQFN ...................................................................7NC/W

Junction-to-Ambient Thermal Resistance (B

16-Pin TQFN .................................................................48NC/W

Operating Temperature Range .......................... -40NC to +85NC

Maximum Junction Temperature .....................................+150NC

Storage Temperature Range ............................ -65NC to +150NC

Lead Temperature (soldering, 10s) ................................+300NC

Soldering Temperature (reflow) ......................................+260NC

= V

CS

MAX5974A/
MAX5974C

MAX5974B/
MAX5974D

CSSC

= V

DITHER/SYNC

= +70NC) (Note 1)

A

) (Note 1)

JC

) (Note 1)

JA

= V

= V

FFB

= V

FB

19.1 19.8 20.4

9.4 9.8 10.25

100 150

1.23 V

100 600 kHz

-8 +8 %

DCLMP

V

FA

V

FA

=

2

Active-Clamped, Spread-Spectrum,

Current-Mode PWM Controllers

ELECTRICAL CHARACTERISTICS (continued)

(VIN = 12V (for MAX5974A/MAX5974C, bring VIN up to 21V for startup), V
V

, VEN = +2V, NDRV = AUXDRV = SS = COMP = unconnected, RRT = 34.8kI, RDT = 25kI, CIN = 1FF, TA = -40NC to +85NC,

GND

unless otherwise noted. Typical values are at T

= +25NC.) (Note 2)

A

CS

= V

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

SYNCHRONIZATION (SYNC)

Synchronization Logic-High
Input

V

IH-SYNC

Synchronization Pulse Width 50 ns

Synchronization Frequency
Range

f

SYNCIN

Maximum Duty Cycle During
Synchronization

DITHERING RAMP GENERATOR (DITHER)

Charging Current V
Discharging Current V

= 0V 45 50 55

DITHER

= 2.2V 43 50 57

DITHER

Ramp’s High Trip Point 2 V
Ramp’s Low Trip Point 0.4 V

SOFT-START AND RESTART (SS)

Charging Current I

Discharging Current

Discharge Threshold to Disable
Hiccup and Restart

Minimum Restart Time During
Hiccup Mode

Normal Operating High Voltage V
Duty-Cycle Control Range V

SS-CH

I

SS-D

I

SS-DH

V

SS-DTH

t

RSTRT-MIN

SS-HI

SS-DMAX

VSS = 2V, normal shutdown 0.65 1.34 2 mA

(VEN < V
V

= 2V, hiccup mode discharge for

SS

t

RESTART

D

MAX

or VIN < V

ENF

(Note 3)

(typ) = (V

SS-DMAX

INUVF

/2.43V) 0 2 V

DUTY-CYCLE CLAMP (DCLMP)

DCLMP Input Current I

Duty-Cycle Control Range V

DCLMP

DCLMP-R

V

D
1 - (V

= 0 to 5V -100 0 +100 nA

DCLMP

V

DCLMP

MAX

(typ) =

DCLMP

2.43V)

/

V

DCLMP

V

DCLMP

NDRV DRIVER

Pulldown Impedance R
Pullup Impedance R

NDRV-N

NDRV-P

I

(sinking) = 100mA 1.9 3.4

NDRV

I

(sourcing) = 50mA 4.7 8.3

NDRV

Peak Sink Current 1 A
Peak Source Current 0.65 A

C

Fall Time t
Rise Time t

NDRV-F

NDRV-R

= 1nF 14 ns

NDRV

C

= 1nF 27 ns

NDRV

CSSC

= V

DITHER/SYNC

= V

FB

2.91 V

1.1 x
f

SW

D

MAX

x f

f

SW

9.5 10 10.5

),

1.6 2 2.4

0.15 V

1024

5 V

= 0.5V 73 75.4 77.5
= 1V 54 56 58

= 2V 14.7 16.5 18.3

= V

SYNC

FFB

2 x

f

SW

/

= V

DCLMP

kHz

%

FA
FA

FA

FA

Clock

Cycles

%

I

I

MAX5974A/MAX5974B/MAX5974C/MAX5974D

=

3

Active-Clamped, Spread-Spectrum,
Current-Mode PWM Controllers

ELECTRICAL CHARACTERISTICS (continued)

(VIN = 12V (for MAX5974A/MAX5974C, bring VIN up to 21V for startup), V
V

, VEN = +2V, NDRV = AUXDRV = SS = COMP = unconnected, RRT = 34.8kI, RDT = 25kI, CIN = 1FF, TA = -40NC to +85NC,

GND

unless otherwise noted. Typical values are at T

= +25NC.) (Note 2)

A

CS

= V

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

AUXDRV DRIVER

Pulldown Impedance R
Pullup Impedance R

AUX-N

AUX-P

I
I

(sinking) = 50mA 4.3 7.7

AUXDRV

(sourcing) = 25mA 10.6 18.9

AUXDRV

Peak Sink Current 0.5 A
Peak Source Current 0.3 A
Fall Time t
Rise Time t

AUX-F

AUX-R

C
C

= 1nF 24 ns

AUXDRV

= 1nF 45 ns

AUXDRV

DEAD-TIME PROGRAMMING (DT)

DT Bias Voltage V

NDRV to AUXDRV Delay
(Dead Time)

DT

From NDRV falling

t

DT

to AUXDRV falling

AUXDRV rising to
NDRV rising

R

DT

R

DT

R

DT

R

DT

CURRENT-LIMIT COMPARATORS (CS)

Cycle-by-Cycle Peak
Current-Limit Threshold

V

CS-PEAK

= V

CSSC

= 10kI
= 100kI
= 10kI
= 100kI

= V

DITHER/SYNC

FB

= V

1.215 V
40

300 350 410

40

310 360 420

375 393 410 mV

FFB

= V

DCLMP

I

I

ns

ns

=

Cycle-by-Cycle Reverse
Current-Limit Threshold

Current-Sense Blanking Time

t

for Reverse Current Limit

Number of Consecutive Peak
Current-Limit Events to Hiccup

Current-Sense Leading-Edge
Blanking Time

Propagation Delay from
Comparator Input to NDRV

Minimum On-Time t

V

CS-REV

CS-BLANK-

REV

N

HICCUP

t

CS-BLANK

t

PDCS

ON-MIN

Turns AUXDRV off for the remaining
cycle if reverse current limit is exceeded

-118 -100 -88 mV

From AUXDRV falling edge 115 ns

8 Events

From NDRV rising edge 115 ns

From CS rising (10mV overdrive) to
NDRV falling (excluding leading-edge

35 ns

blanking)

100 150 200 ns

SLOPE COMPENSATION (CSSC)

Slope Compensation Current
Ramp Height

MAX5974A/MAX5974B/MAX5974C/MAX5974D

PWM COMPARATOR

Comparator Offset Voltage V
Current-Sense Gain A

Current-Sense Leading-Edge
Blanking Time

Comparator Propagation Delay t

PWM-OS

CS-PWM

t

CSSC-BLANK

PWM

Current ramp’s peak added to CSSC
input per switching cycle

V

- V

COMP

DV

COMP

/DV

CSSC

CSSC

(Note 4)

47 52 58

1.35 1.7 2 V

3.1 3.33 3.6 V/V

From NDRV rising edge 115 ns

Change in V
internal leading-edge blanking)

= 10mV (including

CSSC

150 ns

FA

4

Active-Clamped, Spread-Spectrum,

Current-Mode PWM Controllers

ELECTRICAL CHARACTERISTICS (continued)

(VIN = 12V (for MAX5974A/MAX5974C, bring VIN up to 21V for startup), V
V

, VEN = +2V, NDRV = AUXDRV = SS = COMP = unconnected, RRT = 34.8kI, RDT = 25kI, CIN = 1FF, TA = -40NC to +85NC,

GND

unless otherwise noted. Typical values are at T

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

ERROR AMPLIFIER

FB Reference Voltage V

FB Input Bias Current I

Voltage Gain A

Transconductance g

Transconductance Bandwidth BW

Source Current VFB = 1V, V
Sink Current V

FREQUENCY FOLDBACK (FFB)

V
Gain

-to-FFB Comparator

CSAVG

= +25NC.) (Note 2)

A

REF

FB

EAMP

M

10 V/V

VFB when I
V

= 2.5V

COMP

VFB = 0 to 1.75V

Open loop (typical gain
= 1) -3dB frequency

= 1.75V, V

FB

COMP

COMP

COMP

= 0,

= V

CS

= 2.5V 300 375 455

= 1V 300 375 455

= V

CSSC

MAX5974A/
MAX5974B

MAX5974C/
MAX5974D

MAX5974A/
MAX5974B

MAX5974C/
MAX5974D

80 dB

MAX5974A/
MAX5974B

MAX5974C/
MAX5974D

MAX5974A/
MAX5974B

MAX5974C/
MAX5974D

DITHER/SYNC

1.202 1.215 1.227

-250 +250

-500 +100

= V

= V

FB

FFB

1.5 1.52 1.54

1.8 2.55 3.2

1.8 2.66 3.5

2

30

= V

DCLMP

V

nA

mS

MHz

FA
FA

MAX5974A/MAX5974B/MAX5974C/MAX5974D

=

FFB Bias Current I

NDRV Switching Frequency
During Foldback

Note 2: All devices are 100% production tested at T
Note 3: See the Output Short-Circuit Protection with Hiccup Mode section.
Note 4: The parameter is measured at the trip point of latch with V

DV

CSSC

< 0.25V.

FFB

f

SW-FB

V

= 0V, VCS = 0V (not in FFB mode) 26 30 33

FFB

fSW/2 kHz

= +25NC. Limits over temperature are guaranteed by design.

A

= 0V. Gain is defined as DV

FB

COMP

/DV

for 0.15V <

CSSC

FA

5

Active-Clamped, Spread-Spectrum,
Current-Mode PWM Controllers

Typical Operating Characteristics

(VIN = 12V (for MAX5974A/MAX5974C, bring VIN up to 21V for startup), V
V

, VEN = 2V, NDRV = AUXDRV = SS = COMP = unconnected, RRT = 34.8kI, RDT = 25kI, unless otherwise noted.)

GND

CS

= V

CSSC

= V

DITHER/SYNC

= V

FB

= V

FFB

= V

DCLMP

=

IN UVLO WAKE-UP LEVEL

vs. TEMPERATURE

20.1

MAX5974A/MAX5974C

20.0

19.9

19.8

19.7

IN UVLO WAKE-UP LEVEL (V)

19.6

19.5

-40 85
TEMPERATURE (°C)

EN RISING THRESHOLD

vs. TEMPERATURE

1.220

1.218

1.216

1.214

EN RISING THRESHOLD (V)

1.212

1.210

-40 85
TEMPERATURE (°C)

IN UVLO WAKE-UP LEVEL

vs. TEMPERATURE

10.1

MAX5974B/MAX5974D

10.0

MAX5974A/B/C/D toc01

9.9

9.8

9.7

IN UVLO WAKE-UP LEVEL (V)

9.6

603510-15

9.5

-40 85
TEMPERATURE (°C)

603510-15

7.3

7.2

MAX5974A/B/C/D toc02

7.1

7.0

IN UVLO SHUTDOWN LEVEL

6.9

6.8

EN FALLING THRESHOLD

vs. TEMEPRATURE

1.150

1.149

1.148

MAX5974A/B/C/D toc04

1.147

1.146

1.145

1.144

EN FALLING THRESHOLD (V)

1.143

603510-15

1.142

-40 85

TEMPERATURE (°C)

6035-15 10

140

120

MAX5974A/B/C/D toc05

100

UVLO CURRENT (µA)

80

60

IN UVLO SHUTDOWN LEVEL

vs. TEMPERATURE

-40 85
TEMPERATURE (°C)

603510-15

UVLO SHUTDOWN CURRENT

vs. TEMPERATURE

MAX5974A/MAX5974C

MAX5974B/MAX5974D

-40 85
TEMPERATURE (°C)

603510-15

MAX5974A/B/C/D toc03

MAX5974A/B/C/D toc06

SUPPLY CURRENT vs. SUPPLY VOLTAGE

(MAX5974A/MAX5974C)

10,000

1000

MAX5974A/MAX5974B/MAX5974C/MAX5974D

100

SUPPLY CURRENT (µA)

10

0 22

TA = +85°C

MAX5974A/B/C/D toc07

TA = -40°C

2018161412108642

SUPPLY VOLTAGE (V)

SUPPLY CURRENT vs. SUPPLY VOLTAGE

(MAX5974B/MAX5974D)

10,000

1000

100

SUPPLY CURRENT (µA)

10

0 22

TA = +85°C

SUPPLY VOLTAGE (V)

TA = -40°C

2018161412108642

2.4

2.0

MAX5974A/B/C/D toc08

1.6

1.2

0.8

SUPPLY CURRENT (mA)

0.4

0

SUPPLY CURRENT

vs. SWITCHING FREQUENCY

0 800

SWITCHING FREQUENCY (kHz)

6

MAX5974A/B/C/D toc09

700600500400300200100

Active-Clamped, Spread-Spectrum,

Current-Mode PWM Controllers

Typical Operating Characteristics (continued)

(VIN = 12V (for MAX5974A/MAX5974C, bring VIN up to 21V for startup), V
V

, VEN = 2V, NDRV = AUXDRV = SS = COMP = unconnected, RRT = 34.8kI, RDT = 25kI, unless otherwise noted.)

GND

CS

= V

CSSC

= V

DITHER/SYNC

= V

FB

= V

FFB

= V

DCLMP

MAX5974A/MAX5974B/MAX5974C/MAX5974D

=

SOFT-START CHARGING CURRENT

vs. TEMPERATURE

10.06

10.05

10.04

10.03

10.02

10.01

10.00

9.99

SOFT-START CHARGING CURRENT (µA)

9.98

9.97

-40 85
TEMPERATURE (°C)

FREQUENCY DITHERING

vs. R

R

DITHER

DITHER

(kΩ)

14

12

10

8

6

4

FREQUENCY DITHERING (%)

2

0

300 1000

MAXIMUM DUTY CYCLE

vs. SYNC FREQUENCY

45

VSS = 0.5V

40

35

30

25

20

15

MAXIMUM DUTY CYCLE (%)

10

5

0

250 500

SYNC FREQUENCY (kHz)

SWITCHING FREQUENCY

vs. RRT VALUE

1000

MAX5974A/B/C/D toc10

100

SWITCHING FREQUENCY (kHz)

603510-15

10

RRT VALUE (kΩ)

10010

252

251

250

MAX5974A/B/C/D toc11

249

248

247

246

SWITCHING FREQUENCY (kHz)

245

244

MAXIMUM DUTY CYCLE

vs. SWITCHING FREQUENCY

900800700600500400

83

82

81

MAX5974A/B/C/D toc13

80

79

78

77

MAXIMUM DUTY CYCLE (%)

76

75

0 800

700600100 200 300 400 500

SWITCHING FREQUENCY (kHz)

81.0

80.9

80.8

MAX5974A/B/C/D toc14

80.7

80.6

80.5

80.4

MAXIMUM DUTY CYCLE (%)

80.3

80.2

MAXIMUM DUTY CYCLE

vs. V

VSS (V)

SS

2.01.51.00.5

100

90

80

MAX5974A/B/C/D toc17

70

60

50

40

30

MAXIMUM DUTY CYCLE (%)

20

10

0

100

90

80

MAX5974A/B/C/D toc16

70

60

50

40

30

MAXIMUM DUTY CYCLE (%)

20

10

0

450400350300

0 2.5

SWITCHING FREQUENCY

vs. TEMPERATURE

-40 85
TEMPERATURE (°C)

6035-15 10

MAXIMUM DUTY CYCLE

vs. TEMPERATURE

-40 85
TEMPERATURE (°C)

6035-15 10

MAXIMUM DUTY CYCLE

vs. V

DCLMP

0 2.5

V

DCLMP

2.01.51.00.5

(V)

MAX5974A/B/C/D toc12

MAX5974A/B/C/D toc15

MAX5974A/B/C/D toc18

7

Active-Clamped, Spread-Spectrum,
Current-Mode PWM Controllers

Typical Operating Characteristics (continued)

(VIN = 12V (for MAX5974A/MAX5974C, bring VIN up to 21V for startup), V
V

, VEN = 2V, NDRV = AUXDRV = SS = COMP = unconnected, RRT = 34.8kI, RDT = 25kI, unless otherwise noted.)

GND

400

DEAD TIME vs. RDT VALUE

350

300

250

200

DEAD TIME (ns)

150

100

50

0

10 100

RDT VALUE (kΩ)

MAX5974A/B/C/D toc19

DEAD TIME (ns)

908020 30 40 6050 70

DEAD TIME vs. TEMPERATURE

102

100

98

96

94

92

90

88

-40
TEMPERATURE (°C)

CS

= V

CSSC

11085603510-15

= V

DITHER/SYNC

= V

PEAK CURRENT-LIMIT THRESHOLD

vs. TEMPERATURE

398

397

396

MAX5974A/B/C/D toc20

395

394

393

392

391

390

PEAK CURRENT-LIMIT THRESHOLD (mV)

389

388

-40 85
TEMPERATURE (°C)

FB

= V

FFB

= V

DCLMP

603510-15

=

MAX5974A/B/C/D toc21

REVERSE CURRENT-LIMIT THRESHOLD

vs. TEMPERATURE

-97

-98

-99

-100

-101

-102

-103

-104

-105

-106

REVERSE CURRENT-LIMIT THRESHOLD (mV)

-107

-40 85
TEMPERATURE (°C)

603510-15

MAX5974A/B/C/D toc22

SLOPE COMPENSATION CURRENT (mA)

CURRENT-SENSE GAIN

vs. TEMPERATURE

3.40

3.39

3.38

3.37

MAX5974A/MAX5974B/MAX5974C/MAX5974D

3.36

3.35

3.34

3.33

CURRENT-SENSE GAIN (V/V)

3.32

3.31

3.30

-40 85
TEMPERATURE (°C)

603510-15

MAX5974A/B/C/D toc25

FEEDBACK VOLTAGE (V)

SLOPE COMPENSATION CURRENT

vs. TEMPERATURE

54.0

53.5

53.0

52.5

52.0

51.5

51.0

50.5

50.0

-40 85
TEMPERATURE (°C)

FEEDBACK VOLTAGE

vs. TEMPERATURE

1.220

MAX5974C/MAX5974D

1.219

1.218

1.217

1.216

1.215

1.214

1.213

1.212

1.211

1.210

-40 85

TEMPERATURE (°C)

170

165

MAX5974A/B/C/D toc23

160

155

150

NDRV MINIMUM ON-TIME (ns)

145

6035-15 10

603510-15

140

1.522

1.521

MAX5974A/B/C/D toc26

1.520

1.519

1.518

FEEDBACK VOLTAGE (V)

1.517

1.516

NDRV MINIMUM ON-TIME

vs. TEMPERATURE

-40 85
TEMPERATURE (°C)

FEEDBACK VOLTAGE

vs. TEMPERATURE

-40 85

TEMPERATURE (°C)

MAX5974A/B/C/D toc24

603510-15

MAX5974A/B/C/D toc27

603510-15

8