Rainbow Electronics MAX17075 User Manual

General Description

The MAX17075 includes a high-voltage boost regulator,
one high-current operational amplifier, two regulated
charge pumps, and one MLG block for gate-driver
supply modulation.

The step-up DC-DC converter is a 1.2MHz current­mode boost regulator with a built-in power MOSFET. It
provides fast load-transient response to pulsed loads
while producing efficiencies over 85%. The built-in
160mΩ (typ) power MOSFET allows output voltages as
high as 18V boosted from inputs ranging from 2.5V to

5.5V. A built-in 7-bit digital soft-start function controls
startup inrush currents.

The gate-on and gate-off charge pumps provide regu­lated TFT gate-on and gate-off supplies. Both output
voltages can be adjusted with external resistive
voltage-dividers.

The operational amplifier, typically used to drive the
LCD backplane (VCOM), features high-output short-cir­cuit current (±500mA), fast slew-rate (45V/µs), wide
bandwidth (20MHz), and rail-to-rail outputs.

The MAX17075 is available in a 24-pin thin QFN pack­age with 0.5mm lead spacing. The package is a square
(4mm x 4mm) with a maximum thickness of 0.8mm for
ultra-thin LCD design. It operates over the -40°C to
+85°C temperature range.

Applications

Notebook Computer Displays

LCD Monitor Panels

LCD TVs

Features

o 2.5V to 5.5V Input Operating Range

o Current Mode Step-Up Regulator

Fast-Transient Response
Built-In 20V, 3A, 0.16Ω n-Channel Power MOSFET
Cycle-by-Cycle Current Limit
87% Efficiency (5V Input to 13V Output)

1.2MHz Switching Frequency
±1% Output Voltage Regulation Accuracy

o High-Current 18V VCOM Buffer

±500mA Output Short-Circuit Current
45V/µs Slew Rate
20MHz -3dB Bandwidth
Rail-to-Rail Output

o Regulated Charge Pump for TFT Gate-On Supply

o Regulated Charge Pump for TFT Gate-Off Supply

o Logic-Controlled High-Voltage Switches with

Adjustable Delay

o Soft-Start and Timed Delay Fault Latch for All

Outputs

o Overload and Thermal Protection

MAX17075

Boost Regulator with Integrated Charge Pumps,

Switch Control, and High-Current Op Amp

________________________________________________________________

Maxim Integrated Products

1

Ordering Information

Simplified Operating Circuit

19-4353; Rev 0; 11/08

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.

EVALUATION KIT

AVAILABLE

PART TEMP RANGE PIN-PACKAGE

MAX17075ETG+ -40°C to +85°C 24 TQFN-EP*

*

EP = Exposed paddle.

+

Denotes a lead-free/RoHS-compliant package.

Pin Configuration appears at end of data sheet.

V

FROM

SYSTEM

3.3V

MAIN

V

IN

2.5V TO 5.5V

V

AVDD

V

GOFF

TO V

V

IN

R1

10Ω

COM

1μF

BGND

VCC

OUT

MAX17075

NEG

POS

REF

AGND

FBN

DRVN

C5

PGND

COMP

RST

RSTIN

DRN

COM

SRC

DRVP

LX

FB

V

GON

BGND

SUP

CTL EP

FROM
TCON

FBP

DEL

MAX17075

Boost Regulator with Integrated Charge Pumps,
Switch Control, and High-Current Op Amp

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(V

VCC

= +5V, Circuit of Figure 1, V

AVDD

= V

SUP

= +13V, TA= 0°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.

VCC, CTL, RSTIN, RST to AGND ..........................-0.3V to +7.5V

DEL, REF, COMP, FB, FBN,

FBP to AGND .......................................-0.3V to (V

VCC

+ 0.3V)

PGND, BGND to AGND.........................................-0.3V to +0.3V

LX to PGND ............................................................-0.3V to +20V

SUP to PGND .........................................................-0.3V to +20V

DRVN, DRVP to PGND..............................-0.3V to (V

SUP

+ 0.3V)

SRC, COM, DRN to AGND .....................................-0.3V to +36V

DRN to COM............................................................-30V to +30V

SRC to SUP ............................................................................23V

REF Short Circuit to AGND.........................................Continuous

POS, NEG, OUT to AGND...........................-0.3V to (V

SUP

+ 0.3)

DRVN, DRVP RMS Current ...............................................200mA

LX, PGND RMS Current Rating.............................................2.4A

Continuous Power Dissipation (T

A

= +70°C)

24-Pin TQFN (derate 27.8mW/°C above +70°C).......2222mW

Operating Temperature Range ...........................-40°C to +85°C

Junction Temperature......................................................+150°C

Storage Temperature Range .............................-65°C to +160°C

Lead Temperature (soldering, 10s) .................................+300°C

PARAMETER CONDITIONS MIN TYP MAX UNITS

VCC Input Supply Range 2.5 5.5 V

VCC Undervoltage-Lockout (UVLO) Threshold VCC rising, hysteres is (typ) = 50mV 2.05 2.25 2.45 V

VCC Shutdown Current VCC = 2V 100 200 μA

VFB = 1.3V, not switching 1 1.5

VCC Quiescent Current

V

FB

= 1.0V, switching 4 5

mA

REFERENCE

REF Output Voltage No external load 1.238 1.250 1.262 V

REF Load Regulation 0n < I

LOAD

< 50μA 6 mV

REF Sin k Current In regulation 10 μA

REF Undervoltage-Lockout Threshold Ri sing edge, hysteresis (typ) = 200mV 1 1.17 V

OSCILLATOR AND TIMING

Frequency 1000 1200 1400 kHz

Oscillator Maximum Duty Cycle 87 90 93 %

Duration to Trigger Fault Cond ition FB or FBP or FBN below threshold 47 55 65 ms

DEL Capacitor Charge Current During startup, V

DEL

= 1.0V 4 5 6 μA

DEL Turn-On Thresho ld 1.19 1.25 1.31 V

DEL Discharge Switch On-Resistance 20 

STEP-UP R EGULATOR

Output Voltage Range V

VCC

18 V

FB Regulation Voltage FB = COMP, C

COMP

= 1nF 1.238 1.250 1.262 V

FB Fault Trip Level Falling edge 0.96 1 1.04 V

FB Load Regulation 0 < I

LOAD

< full, transient only -1 %

FB Line Regulation VCC = 2.5V to 5.5V -0.2 0 +0.2 %/V

FB Input Bia s Current VFB = 1.25V 50 125 200 nA

FB Tran sconductance I = ±2.5μA at COMP, FB = COMP 75 160 280 μS

FB Voltage Gain FB to COMP 2600 V/V

MAX17075

Boost Regulator with Integrated Charge Pumps,

Switch Control, and High-Current Op Amp

_______________________________________________________________________________________ 3

PARAMETER CONDITIONS MIN TYP MAX UNITS

LX Current Lim it VFB = 1.1V, duty cycle = 75% 2.5 3.0 3.5 A

LX On-Resistance I

LX =

200mA 0.16 0.25 

LX Leakage Current V

LX =

19V, TA = +25°C 10 20 μA

Current-Sense Transresis tance 0.1 0.2 0.3 V/A

Soft-Start Period 7-bit current ramp 14 m s

POSITIVE CHARGE-PUMP REGULATOR

V

SUP

Input Supply Range 6 18 V

V

SUP

Overvoltage Threshold V

SUP

= r ising, hysteresi s = 200mV 19 20 21 V

Operating Frequency

0.5 x
f

OSC

Hz

FBP Regulation Voltage -1.5% 1.250 +1.5% V

FBP Line Regulation Error V

SUP

= 12V to 18V, V

GON

= 30V 0.2 %/V

FBP Input Bias Current V

FBP

= 1.5V, TA = +25°C -50 +50 nA

DRVP Current Limit Not in dropout 400 mA

DRVP PCH On-Resistance 4 6 

DRVP NCH On-Resistance 1.5 3 

FBP Fau lt Trip Level Falling edge 0.96 1 1.04 V

Positive Charge-Pump Soft-Start Period

7-bit vo ltage ramp with filtering to prevent
high peak currents

3 5 ms

NEGATIVE CHARGE-PUMP REGULATOR

V

SUP

Input Supply Range 6 18 V

Operating Frequency

0.5 x
f

OSC

Hz

FBN Regulation Voltage (V

REF

- V

FBN

) V

REF

- V

FBN

= 1V -1.5% 1 +1.5% V

FBN Input Bias Current V

FBN

= 0, TA = +25°C -50 +50 nA

FBN Line Regulation Error V

SUP

= 9V to 18V, V

GOFF

= -7V 0.2 %/V

DRVN PCH On-Resistance 4 6 

DRVN NCH On-Resistance 1.5 3 

DRVN Current Limit Not in dropout 400 mA

FBN Fault Trip level Rising edge 450 mV

Negative Charge-Pump Soft-Start Period

7-bit vo ltage ramp with filtering to prevent
high peak currents

3 5 ms

POSITIVE GATE DRIVER TIMING AND CONTROL SWITCHES

CTL Input Low Voltage 0.6 V

CTL Input H igh Voltage 2 V

CTL Input Current V

CTL

= 0 or V

VCC

, TA = +25°C -1 +1 μA

CTL-to-COM Rising Propagation Dela y C

LOAD

= 100pF 250 ns

SRC Input Voltage Range 36 V

SRC-to-COM Switch On-Resistance V

DEL

= 1.5V, CTL = VCC 5 10 

ELECTRICAL CHARACTERISTICS (continued)

(V

VCC

= +5V, Circuit of Figure 1, V

AVDD

= V

SUP

= +13V, TA= 0°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.)

MAX17075

Boost Regulator with Integrated Charge Pumps,
Switch Control, and High-Current Op Amp

4 _______________________________________________________________________________________

ELECTRICAL CHARACTERISTICS (continued)

(V

VCC

= +5V, Circuit of Figure 1, V

AVDD

= V

SUP

= +13V, TA= 0°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.)

PARAMETER CONDITIONS MIN TYP MAX UNITS

DRN-to-COM Switch On-Resistance V

DEL

= 1.5V, CTL = AGND 30 60 

COM-to-GND Pulldown V

DEL

= 0 1.5 2.5 k

V

DEL

= 1.5V, CTL = VCC 300 600

SRC Input Current

V

DEL

= 1.5V, CTL = AGND 200 360

μA

OPERATIONAL AMPLIFIERS

SUP Supply Range 6 18 V

VSUP Undervoltage Threshold 3.8 4 4.2 V

SUP Suppl y Current Buffer configuration, V

POS

= V

SUP

/2, no load 4 6.5 mA

Input Offset Voltage V

NEG

, V

POS

= V

SUP

/2, TA = +25°C 12 mV

Input Bias Current V

NEG

, V

POS

= V

SUP

/2, TA = +25°C -1 +1 μA

Input Common-Mode Voltage Range 0 V

SUP

V

Input Common-Mode Rejection Ratio 80 dB

Output-Voltage-Swing High I

OUT =

50mA

V

SUP

-

350

mV

Output-Voltage-Swing Low I

OUT =

-50mA 350 mV

Large-Signal Voltage Gain V

OUT

= 1V to (V

SUP

- 1)V 80 dB

Slew Rate 45 V/μs

-3dB Bandwidth 20 MHz

Sourcing 500

Short-Circuit Current

Sinking 500

mA

XAO CONTROL

Fal ling edge at VCC = 5V 1.225 1.250 1.275

RSTIN Threshold

Fal ling edge at V

CC

= 1.8V 1.213 1.250 1.287

V

RSTIN Input Current TA = +25°C -1 +1 μA

RSTIN Hysteresis 50 mV

RST Output Voltage I

SINK

= 1mA 0.4 V

RST Blan king Time Counting from V

VCC

crossing 2.25V 160 220 280 ms

XAO UVLO V

VCC

rising with h ysteresis of 50mV 1.5 1.7 V

MAX17075

Boost Regulator with Integrated Charge Pumps,

Switch Control, and High-Current Op Amp

_______________________________________________________________________________________ 5

ELECTRICAL CHARACTERISTICS

(VCC= +5V, Circuit of Figure 1, V

AVDD

= V

SUP

= +13V, TA= -40°C to +85°C, unless otherwise noted.) (Note 1)

PARAMETER CONDITIONS MIN TYP MAX UNITS

V

CC

Input Supply Range 2.5 5.5 V

VCC Undervoltage-Lockout Threshold VCC rising, hystere s is (typ) = 50mV 2.05 2.45 V

VCC Shutdown Current 200 μA

VFB = 1.3V, not switching 1.5

V

CC

Quiescent Current

V

FB

= 1.0V, switching 5

mA

REFERENCE

REF Output Voltage No external load 1.230 1.267 V

REF Load Regulation 0 < I

LOAD

< 50μA 6 mV

REF Sin k Current In regulation 10 μA

REF Undervoltage-Lockout Threshold Ri sing edge, hysteresis (typ) = 200mV 1.15 V

OSCILLATOR AND TIMING

Frequency 1000 1400 kHz

Oscillator Maximum Duty Cycle 86 94 %

Duration to Trigger Fault Cond ition FB or FBP or FBN below threshold 47 65 ms

DEL Capacitor Charge Current During startup, V

DEL

= 1.0V 4 6 μA

DEL Turn-On Thresho ld 1.19 1.31 V

STEP-UP R EGULATOR

Output Voltage Range VIN 18 V

FB Regulation Voltage FB = COMP, C

COMP

= 1nF 1.230 1.267 V

FB Fault Trip Level Falling edge 0.96 1.04 V

FB Line Regulation VCC = 2.5V to 5.5V -0.25 +0.25 %/V

FB Input Bia s Current VFB = 1.25V 50 200 nA

FB Tran sconductance I = ±2.5μA at COMP, FB = COMP 75 280 μS

LX Current Lim it VFB = 1.1V, duty cycle = 75% 2.5 3.5 A

LX On-Resistance I

LX =

200mA 0.25 

Current-Sense Tran sresi stance 0.10 0.30 V/A

POSITIVE CHARGE-PUMP REGULATOR

V

SUP

Input Supply Range 6 18 V

V

SUP

Overvoltage Threshold V

SUP

= r ising, hysteresi s = 200mV 19 21 V

FBP Regulation Voltage -2% 1.25 +2% V
FBP Line Regulation Error V

SUP

= 8V to 18V, V

GON

= 30V 0.2 %/V

FBP Input Bias Current V

FBP

= 1.5V, TA = +25°C -50 +50 nA

DRVP PCH On-Resistance 6 

DRVP NCH On-Resistance 3 
FBP Fau lt Trip Level Falling edge 0.96 1.04 V

Positive Charge-Pump Soft-Start Period

7-bit vo ltage ramp with filtering to prevent
high peak currents

5 ms

MAX17075

Boost Regulator with Integrated Charge Pumps,
Switch Control, and High-Current Op Amp

6 _______________________________________________________________________________________

ELECTRICAL CHARACTERISTICS (continued)

(VCC= +5V, Circuit of Figure 1, V

AVDD

= V

SUP

= +13V, TA= -40°C to +85°C, unless otherwise noted.) (Note 1)

PARAMETER CONDITIONS MIN TYP MAX UNITS

NEGATIVE CHARGE-PUMP REGULATOR

V

SUP

Input Supply Range 6 18 V

FBN Regulation Voltage (V

REF

- V

FBN

) V

REF

- V

FBN

= 1V -2% 1

+2%

V

FBN Input Bias Current V

FBN

= 0, TA = +25°C -50 +50 nA

FBN Line Regulation Error V

SUP

= 9V to 18V, V

GOFF

= -7V 0.2 %/V
DRVN PCH On-Resistance 6 
DRVN NCH On-Resistance 3 

Negative Charge-Pump Soft-Start Period

7-bit vo ltage ramp with filtering to prevent
high peak currents

5 ms

POSITIVE GATE-DRIVER TIMING AND CONTROL SWITCHES

CTL Input Low Voltage 0.6 V

CTL Input H igh Voltage 2 V
CTL Input Current V

CTL

= 0 or V

VCC

, TA = +25°C -1 +1 μA
SRC Input Voltage Range 36 V
SRC-to-COM Switch On-Resistance V

DEL

= 1.5V, CTL = VCC 10 

DRN-to-COM Switch On-Resistance V

DEL

= 1.5V, CTL = AGND 60 

COM-to-GND Pulldown V

DEL

= 0 1.5 2.5 k

V

DEL

= 1.5V, CTL = VCC 600 μA

SRC Input Current

V

DEL

= 1.5V, CTL = AGND 360 μA

OPERATIONAL AMPLIFIERS

SUP Supply Range 6 18 V
V

SUP

Undervo ltage Threshold 3.8 4 4.2 V

SUP Suppl y Current Buffer configuration, V

POS = VSUP

/2, no load 6.5 mA

Input Offset Voltage V

NEG

, V

POS

= V

SUP

/2, TA = +25°C 8 mV

Input Bias Current V

NEG

, V

POS

= V

SUP

/2, TA = +25°C -1 +1 μA

Input Common-Mode Voltage Range 0 V

SUP

V

Output-Voltage-Swing High I

OUT =

50mA

V

SUP

-

350

mV

Output-Voltage-Swing Low I

OUT =

-50mA 350 mV

Sourcing 500

Short-Circuit Current

Sinking 500

mA

XAO CONTROL

RSTIN Threshold Fa lling edge 1.22 1.28 V

RSTIN Input Current TA = +25°C -1 +1 μA
RST Output Voltage I

SINK

= 1mA 0.4 V

RST Blan king Time Counting from V

VCC

crossing 2.25V 160 280 ms

XAO UVLO VCC rising with typical hysteresis of 50mV 1.7 V

Note 1: -40°C specifcations are guaranteed by design, not production tested.

MAX17075

Boost Regulator with Integrated Charge Pumps,

Switch Control, and High-Current Op Amp

_______________________________________________________________________________________

7

Typical Operating Characteristics

(TA = +25°C, unless otherwise noted.)

Typical Operating Characteristics

(TA = +25°C, unless otherwise noted.)

STEP-UP REGULATOR EFFICIENCY

vs. LOAD CURRENT

100

90

80

70

60

50

40

EFFICIENCY (%)

30

20

10

0

1 1000

VIN = 5V

VIN = 3.3V

VIN = 2.5V

10010

LOAD CURRENT (mA)

STEP-UP REGULATOR SWITCHING

FREQUENCY vs. INPUT VOLTAGE

1.24
150mA LOAD

1.23

1.22

1.21

1.20

1.19

1.18

SWITCHING FREQUENCY (MHz)

1.17

1.16

2.5 5.0
INPUT VOLTAGE (V)

MAX17075 toc01

OUTPUT ERROR (%)

STEP-UP REGULATOR OUTPUT VOLTAGE

vs. LOAD CURRENT

0.6

0.4

0.2

0

-0.2

-0.4

-0.6

-0.8

-1.0
0 1000

LOAD CURRENT (mA)

MAX17075 toc04

4.53.0 3.5 4.0

700 800 900100 200 300 400 500 600

0V

0V

0A

0V

STEP-UP REGULATOR LINE REGULATION

UNDER DIFFERENT LOADS

0.20

0.15

MAX17075 toc02

0.10

NO

0.05
LOAD

0

200mA LOAD

-0.05

OUTPUT ERROR (%)

-0.10

-0.15

-0.20

100mA LOAD

2.5 5.0

STEP-UP REGULATOR STARTUP

WITH HEAVY LOAD (600mA)

2ms/div

MAX17075 toc05

300mA LOAD

INPUT VOLTAGE (V)

V

IN

5V/div
V

AVDD

5V/div

I

L

1A/div

LX
10V/div

MAX17075 toc03

4.53.0 3.5 4.0

STEP-UP REGULATOR LOAD-TRANSIENT

RESPONSE (100mA TO 800mA)

0V

0A

0A

R

= 82kΩ

COMP

= 220pF

C

COMP1

= 18pF

C

COMP2

40μs/div

MAX17075 toc06

V

AVDD

(AC-COUPLED)
500mV/div

I

L

2A/div

LOAD CURRENT
500mA/div

LOAD-TRANSIENT RESPONSE (80mA TO 2.08mA)

STEP-UP REGULATOR PULSED

0V

0A

0A

R

= 82kΩ

COMP

= 220pF

C

COMP1

= 18pF

C

COMP2

10μs/div

MAX17075 toc07

V

AVDD

(AC-COUPLED)
500mV/div

I

L

2A/div

LOAD CURRENT
1A/div