Rainbow Electronics MAX1701 User Manual

General Description

The MAX1700/MAX1701 are high-efficiency, low-noise,
step-up DC-DC converters intended for use in battery­powered wireless applications. They use a synchro­nous-rectified pulse-width-modulation (PWM) boost
topology to generate 2.5V to 5.5V outputs from battery
inputs such as one to three NiCd/NiMH cells or one Li­Ion cell. Both devices have an internal 1A, 130mΩ N-
channel MOSFET switch and a 250mΩ P-channel
synchronous rectifier.

With their internal synchronous rectifier, the MAX1700/
MAX1701 deliver 5% better efficiency than similar non­synchronous converters. They also feature a pulse­frequency-modulation (PFM) standby mode to improve
efficiency at light loads, and a 3µA shutdown mode.

The MAX1700/MAX1701 come in 16-pin QSOP pack­ages (which occupy the same space as an 8-pin SO).
The MAX1701 includes two comparators to generate
power-good and low-battery warning outputs. It also
contains a gain block that can be used to build a linear
regulator using an external P-channel pass device.

For higher-power outputs, refer to the MAX1703. For
dual outputs (step-up and linear regulator), refer to the
MAX1705/MAX1706. For an on-board analog-to-digital
converter, refer to the MAX848/MAX849.

The MAX1701 evaluation kit is available to speed design
time.

Applications

Digital Cordless Phones Personal Communicators
PCS Phones Palmtop Computers
Wireless Handsets Hand-Held Instruments
Two-Way Pagers

Features

♦ Up to 96% Efficiency
♦ 1.1 VINGuaranteed Start-Up
♦ 0.7V to 5.5V Input Range
♦ Up to 800mA Output
♦ Step-Up Output (adjustable from 2.5V to 5.5V)
♦ PWM/PFM Synchronous-Rectified Topology
♦ External Clock or Internal 300kHz Oscillator
♦ 3µA Logic-Controlled Shutdown
♦ Power-Good Output (MAX1701)
♦ Low-Battery Comparator (MAX1701)
♦ Uncommitted Gain Block (MAX1701)

MAX1700/MAX1701

1-Cell to 3-Cell, High-Power (1A),

Low-Noise, Step-Up DC-DC Converters

________________________________________________________________

Maxim Integrated Products

1

PGNDGNDFB

ONA

REF

ONB

POUT

LX

OUT

ON

INPUT

0.7V TO 5.5V

OR

OFF

OFF

ON

SYNC

PWM

PFM

OUTPUT

3.3V OR ADJ

UP TO 800mA

CLK/SEL

MAX1700

Pin Configurations

TOP VIEW

16
15
14
13
12
11
10

9

1
2
3
4
5
6
7
8

I.C. I.C.

POUT
OUT
LX
PGND
FB
I.C.
I.C.

I.C. = INTERNAL CONNECTION. LEAVE OPEN OR CONNECT TO GND

MAX1700

QSOP

I.C.

REF

I.C.

CLK/SEL

GND

ONB
ONA

Typical Operating Circuit

19-4759; Rev 1; 1/99

PART

MAX1700EEE

-40°C to +85°C

TEMP. RANGE PIN-PACKAGE

16 QSOP

EVALUATION KIT MANUAL

FOLLOWS DATA SHEET

Ordering Information

MAX1701EEE

-40°C to +85°C 16 QSOP

Pin Configurations continued at end of data sheet.

For free samples & the latest literature: http://www.maxim-ic.com, or phone [phone].
For small orders, phone [phone].

MAX1700/MAX1701

1-Cell to 3-Cell, High-Power (1A),
Low-Noise, Step-Up DC-DC Converters

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(CLK/SEL = ONA = ONB = FB = PGND = GND, OUT = POUT, V

OUT

= 3.6V (Note 6); MAX1701: AIN = LBN = GND, LBP = REF,

T

A

= 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.

ONA, ONB, OUT, AO, POK, LBO to GND...................-0.3V, +6V

PGND to GND.....................................................................±0.3V

LX to PGND.....................................................-0.3V,V

POUT

+0.3V

CLK/SEL, AIN, REF, FB, LBP, LBN, POUT to GND............-0.3V,

V

OUT

+0.3V ...................................................................................

Continuous Power Dissipation (T

A

=+70°C)

16-QSOP (Derate 8.30mW/°C above +70°C) ...............667mW

Operating Temperature Ranges

MAX1700EEE, MAX1701EEE ...........................-40°C to +85°C

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

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

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

CLK/SEL = GND

CLK/SEL = GND

CLK/SEL = OUT

I

LOAD

< 1mA, TA= +25°C

P-channel

N-channel

VLX= V

ONB

= V

OUT

= 5.5V

VLX= 0V, V

OUT

= 5.5V

V

ONB

= 3.6V

CLK/SEL = OUT, No load to full load

CLK/SEL = OUT (MAX1701)

CLK/SEL = OUT (MAX1700)

(Note 4)

V

OUT

= 1.5V

VFB< 0.1V, CLK/SEL = OUT, V

BATT

= 2.4V,

includes load regulation error for 0A ≤ I

LX

≤ 0.55A

Adjustable output, CLK/SEL = OUT, V

BATT

= 2.4V,

includes load regulation error for 0A ≤ I

LX

≤ 0.55A

CLK/SEL = GND (MAX1701)

VFB= 1.25V

CLK/SEL = GND (MAX1700)

CONDITIONS

mA20 120P-Channel Turn-Off Current

mA

250 400 550

N-Channel Current Limit

1100 1300 1600

Ω

0.25 0.5

Switch On-Resistance 0.13 0.28

0.2 0.45

µA0.1 20LX Leakage Current

µA0.1 20POUT Leakage Current

µA

140 300

125 250

Supply Current in Low-Noise
Mode (Note 6)

µA

55 110

Supply Current in Low-Power
Mode (Note 6)

35 70

V0.9 1.1

Minimum Start-Up Voltage
(Note 2)

V0.7 5.5Input Voltage Range (Note 1)

µA

320

Supply Current in Shutdown

%-1.6Load Regulation (Note 5)

V2.0 2.15 2.3

Output Voltage Lockout
Threshold

V2.5 5.5Output Voltage Adjust Range

kHz40 150 300Frequency in Start-Up Mode

V3.17 3.30 3.38Output Voltage (Note 3)

V1.210 1.24 1.255FB Regulation Voltage

nA0.01 20FB Input Current

UNITSMIN TYP MAXPARAMETER

CLK/SEL = GND
CLK/SEL = OUT

DC-DC CONVERTER

DC-DC SWITCHES

MAX1701

MAX1700 0.1 20

Input High Voltage (Note 7)

MAX1700/MAX1701

1-Cell to 3-Cell, High-Power (1A),

Low-Noise, Step-Up DC-DC Converters

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(CLK/SEL = ONA = ONB = FB = PGND = GND, OUT = POUT, V

OUT

= 3.6V (Note 6); MAX1701: AIN = LBN = GND, LBP = REF,

T

A

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

-1µA < I

REF

< 50µA

I

REF

= 0

V

AIN

= 1.5V

I

SINK

= 1mA, V

OUT

= 3.6V or I

SINK

= 20µA, V

OUT

= 1V

To maintain input offset < ±5mV (at least one input must
be within this range)

IAO= 20µA

LBP falling, 15mV hysteresis

V

OUT

= V

POK

= 5.5V

I

SINK

= 1mA, V

OUT

= 3.6V or I

SINK

= 20µA, V

OUT

= 1V

Rising V

FB

Rising V

OUT

, VFB< 0.1V

10µA < IAO= 100µA
V

AIN

= 0.7V, IAO= 100µA

V

AIN

= 1.5V, VAO= 5.5V

CONDITIONS

mV515REF Load Regulation

V1.237 1.250 1.263Reference Output Voltage

V0.03 0.4LBO Output Low Voltage

V0.5 1.5

LBN, LBP Common Mode
Range

mV-5 ±0.5 5LBN, LBP Input Offset

µA0.01 1POK High Leakage Current

nA-30 30AIN Input Current

V1.237 1.25 1.263AIN Reference Voltage

V0.03 0.4POK Low Voltage

V1.1 1.12 1.14External Trip Level

V2.93 2.97 3.02Internal Trip Level

mmho5916Transconductance

V0.1 0.4AO Output Low Voltage

µA0.01 1AO Output High Leakage

UNITSMIN TYP MAXPARAMETER

V

LBP

= V

LBN

= 1.5V

V

OUT

= V

LBO

= 5V

nA20LBN, LBP Input Current

µA0.01 1LBO High Leakage

2.5V < V

OUT

< 5V mV0.2 5REF Supply Rejection

1.2V < V

OUT

< 5.5V, ONA and ONB

0.2V

OUT

1.2V < V

OUT

< 5.5V, ONA and ONB

2.5V < V

OUT

< 5.5V, CLK/SEL

0.8V

OUT

V

0.2V

OUT

Input Low Voltage (Note 7)

2.5V < V

OUT

< 5.5V, CLK/SEL

V

0.8V

OUT

Input High Voltage (Note 7)

CLK/SEL = OUT

ONA, ONB, and CLK/SEL

kHz260 300 340Internal Oscillator Frequency

µA-1 1Logic Input Current

kHz200 400

External Clock Frequency
Range

%80 86 90Oscillator Maximum Duty Cycle

ns100

Maximum CLK/SEL Rise/Fall
Time

ns200Minimum CLK/SEL Pulse Width

GAIN BLOCK (MAX1701)

POWER GOOD (MAX1701)

LOW-BATTERY COMPARATOR

REFERENCE

LOGIC AND CONTROL INPUTS

MAX1700/MAX1701

1-Cell to 3-Cell, High-Power (1A),
Low-Noise, Step-Up DC-DC Converters

4 _______________________________________________________________________________________

ELECTRICAL CHARACTERISTICS (continued)

(CLK/SEL = ONA = ONB = FB = PGND = GND, OUT = POUT, V

OUT

= 3.6V (Note 6); MAX1701: AIN = LBN = GND, LBP = REF,

T

A

= -40°C to +85°C, unless otherwise noted.) (Note 8)

LBP falling, 15mV hysteresis

Rising V

FB

Adjustable output, CLK/SEL = OUT, V

BATT

= 2.4V,

includes load regulation error for 0A ≤ I

LX

≤ 0.55A

10µA < IAO< 100µA

IAO= 20µA

VFB< 0.1V, CLK/SEL = OUT, V

BATT

= 2.4V, includes load

regulation error for 0A ≤ I

LX

≤ 0.55A

CLK/SEL = OUT

Rising V

OUT

, VFB< 0.1V

P-channel

N-channel

V

(Note 4)
V

ONB

= 3.6V

CLK/SEL = GND (MAX1700)

2.92 3.03

CLK/SEL = OUT (MAX1700)

Internal Trip Level

CONDITIONS

mV-5 5LBN, LBP Input Offset

V1.1 1.14External Trip Level

mmho516Transconductance

V1.23 1.27

To maintain input offset < ±5mV (at least one input must
be within this range)

AIN Reference Voltage

mA

250 600

N-Channel Current Limit

1100 1800

V0.5 1.5

LBN, LBP Common Mode
Range

I

REF

= 0 V1.23 1.27Reference Output Voltage

V1.20 1.27FB Regulation Voltage

V3.17 3.38Output Voltage (Note 3)

Ω

0.5

Switch On-Resistance

0.28

0.45

V2.0 2.3

Output Voltage Lockout
Threshold

µA20Supply Current in Shutdown
µA

70

Supply Current in Low-Power
Mode (Note 6)

µA

250

Supply Current in Low-Noise
Mode (Note 6)

UNITSMIN TYP MAXPARAMETER

CLK/SEL = GND (MAX1701)

CLK/SEL = OUT (MAX1701)

CLK/SEL = GND
CLK/SEL = OUT

CLK/SEL = GND

110

300

DC-DC CONVERTER

DC-DC SWITCHES

GAIN BLOCK (MAX1701)

POWER-GOOD (MAX1701)

LOW-BATTERY COMPARATOR (MAX1701)

REFERENCE

Input High Voltage (Note 7)

MAX1700/MAX1701

1-Cell to 3-Cell, High-Power (1A),

Low-Noise, Step-Up DC-DC Converters

_______________________________________________________________________________________ 5

Note 1: Operating voltage. Since the regulator is bootstrapped to the output, once started it will operate down to 0.7V input.
Note 2: Start-up is tested with the circuit of Figure 2.
Note 3: In low-power mode (CLK/SEL = GND), the output voltage regulates 1% higher than low-noise mode (CLK/SEL = OUT or

synchronized).

Note 4: The regulator is in start-up mode until this voltage is reached. Do not apply full load current.
Note 5: Load regulation is measured from no-load to full load where full load is determined by the N-channel switch current limit.
Note 6: Supply current from the 3.30V output is measured between the 3.30V output and the OUT pin. This current correlates

directly to the actual battery supply current, but is reduced in value according to the step-up ratio and efficiency. Set V

OUT

= 3.6V to keep the internal switch open when measuring the current into the device.

Note 7: ONA and ONB have hysteresis of approximately 0.15xV

OUT

.

Note 8: Specifications to -40°C are guaranteed by design and not production tested.

ELECTRICAL CHARACTERISTICS (continued)

(CLK/SEL = ONA = ONB = FB = PGND = GND, OUT = POUT, V

OUT

= 3.6V, MAX1701: AIN = LBN = GND, LBP = REF,

T

A

= -40°C to +85°C, unless otherwise noted.) (Note 8)

CONDITIONS

2.5V < V

OUT

< 5.5V, CLK/SEL

1.2V < V

OUT

< 5.5V, ONA and ONB

0.2V

OUT

V

0.2V

OUT

Input Low Voltage (Note 7)

1.2V < V

OUT

< 5.5V, ONA and ONB

0.8V

OUT

Input High Voltage (Note 7)

ONA, ONB, and CLK/SEL

2.5V < V

OUT

< 5.5V, CLK/SEL

µA-1 1Logic Input Current

V

0.8V

OUT

CLK/SEL = OUT kHz260 340Internal Oscillator Frequency

UNITSMIN TYP MAXPARAMETER

%80 92Oscillator Maximum Duty Cycle

kHz200 400

External Clock Frequency
Range

Typical Operating Characteristics

(TA = +25°C, unless otherwise noted.)

100

90

40

0.1 1 10 100 1000

EFFICIENCY vs. LOAD CURRENT

(V

OUT

= 3.3V)

50

MAX1700-01

LOAD CURRENT (mA)

EFFICIENCY (%)

60

70

80

PFM
PWM

VIN = 0.9V

VIN = 1.2V

VIN = 2.4V

MAX1700-02

100

90

40
30

0.1 1 10 100 1000

EFFICIENCY vs. LOAD CURRENT

(V

OUT

= 5V)

50

LOAD CURRENT (mA)

EFFICIENCY (%)

60

70

80

VIN = 1.2V

VIN = 2.4V

VIN = 3.6V

PFM
PWM

0

2.0

1.0

4.0

3.0

6.0

5.0

7.0

0231 456

MAX1701

SHUTDOWN CURRENT

vs. INPUT VOLTAGE (V)

MAX1770-03

INPUT VOLTAGE (V)

SHUTDOWN CURRENT (µA)

T = 85°C

T = 25°C

T = -40°C

LOGIC AND CONTROL INPUTS