19-1660; Rev 3; 1/07
IT
TION K
VALUA
E
BLE
AVAILA
0.8A, Low-Noise, 1MHz,
Step-Up DC-DC Converter
General Description
Features
♦
Up to 94% Efficiency
♦
0.7V to 5.5V Input Range
♦
Up to 800mA Output
♦
♦
♦
♦
♦
♦
♦
♦
♦
Fixed 3.3V Output (or Adjustable from 2.5V to 5.5V)
PWM Synchronous-Rectified Topology
Low-Noise, Constant-Frequency Operation (1MHz)
0.1µA Logic-Controlled Shutdown
Synchronizable Switching Frequency
Adjustable Current Limit
Adjustable Soft-Start
10-Pin
µMAX
Package
10-Pin 3mm x 3mm TDFN Package
MAX1760/MAX1760H
The MAX1760/MAX1760H are high-efficiency, low-noise,
step-up DC-DC converters intended for use in battery-
powered wireless applications. They combine low quies-
cent supply current (100µA) with a high 1MHz operating
frequency. Small external components and tiny 10-pin
TDFN and µMAX
®
packages make this device an excel-
lent choice for small hand-held applications. The
MAX1760 is activated by a logic-low
ON
signal while the
MAX1760H is activated by a logic-high ON input.
Both devices use a synchronous-rectified pulse-width-
modulation (PWM) boost topology to generate 2.5V to
5.5V outputs from a wide range of inputs, such as 1 to 3
alkaline or NiCd/NiMH cells or a single lithium-ion (Li+)
cell. Proprietary Idle-Mode™ circuitry significantly
improves light-load efficiency and smoothly transitions to
fixed-frequency PWM operation at higher load currents.
Low-noise, forced-PWM mode is available for applica-
tions requiring constant-frequency operation at all load
currents. PWM operation can also be synchronized to
an external clock to protect sensitive frequency bands
in communications equipment. Analog soft-start and
adjustable current limit permit optimization of efficiency,
external component size, and output voltage ripple.
Ordering Information
PART
MAX1760ETB
MAX1760EUB
MAX1760HETB
MAX1760HEUB
PIN-
PACKAGE
10 TDFN-EP*
10 µMAX
10 TDFN-EP*
10 µMAX
ON
LOGIC
Low
Low
High
High
PKG CODE
T1033-1
U10-2
T1033-1
U10-2
Applications
Digital Cordless Phones
Wireless Handsets
Palmtop Computers
Two-Way Pagers
PCS Phones
Handheld Instruments
Personal Communicators
*EP
= Exposed paddle.
Note:
All devices are specified over the -40°C to +85°C operating
temperature range.
Typical Operating Circuit
INPUT = 0.7V
TO V
OUT
Pin Configurations
TOP VIEW
MAX1760
ON
CLK/SEL
LX
POUT
V
OUT
= 3.3V,
800mA
ISET
1
REF
GND
FB
OUT
2
3
4
5
10
ON (ON)
9
POUT
LX
PGND
CLK/SEL
ISET
REF
GND
FB
OUT
1
2
3
4
5
TDFN
(3mm x 3mm)
10
9
ON (ON)
POUT
LX
PGND
CLK/SEL
MAX1760
MAX1760H
8
7
6
MAX1760
MAX1760H
8
7
6
ISET
REF
FB
GND
OUT
PGND
µMAX
(ON) FOR MAX1760H
µMAX is a registered trademark of Maxim Integrated Products, Inc.
Idle Mode is a trademark of Maxim Integrated Products, Inc.
________________________________________________________________
Maxim Integrated Products
1
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.
0.8A, Low-Noise, 1MHz,
Step-Up DC-DC Converter
MAX1760/MAX1760H
ABSOLUTE MAXIMUM RATINGS
ON,
ON,
OUT, CLK/SEL to GND ..................................-0.3V to +6V
PGND to GND ..........................................................................±0.3V
LX to PGND .................................................-0.3V to (V
POUT
+ 0.3V)
POUT to OUT ...........................................................................±0.3V
REF, FB, ISET, POUT to GND.......................-0.3V to (V
OUT
+ 0.3V)
Continuous Power Dissipation (T
A
= +70°C)
Single-Layer Board:
10-Pin µMAX
(derate 5.6mW/°C above +70°C).................................….444mW
10-Pin TDFN-EP (derate 18.5mW/°C above +70°C) .....1482mW
Multilayer Board:
10-Pin µMAX (derate 8.8mW/°C above +70°C) ..........….707mW
10-Pin TDFN-EP (derate 24.4mW/°C above +70°C) .....1951mW
Operating Temperature Range................................-40°C to +85°C
Junction Temperature ...........................................................+150°C
Storage Temperature Range .................................-65°C to +150°C
Lead Temperature (soldering, 10s)......................................+300°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.
ELECTRICAL CHARACTERISTICS
(CLK/SEL = FB = PGND = GND, ISET = REF, OUT = POUT, V
OUT
= 3.6V,
T
A
= 0°C to +85°C.
Typical values are at T
A
= +25°C,
unless otherwise noted.)
PARAMETER
DC-DC CONVERTER
Input Voltage Range
Minimum Startup Voltage
Temperature Coefficient of Startup Voltage
Frequency in Startup Mode
Internal Oscillator Frequency
Oscillator Maximum Duty Cycle
External Clock Frequency Range
Output Voltage
FB Regulation Voltage
FB Input Leakage Current
Load Regulation
Output Voltage Adjust Range
Output Voltage Lockout Threshold
ISET Input Leakage Current
Supply Current in Shutdown
No-Load Supply Current
No-Load Supply Current Forced-PWM Mode
DC-DC SWITCHES
POUT Leakage Current
LX Leakage Current
V
LX
= 0, V
OUT
= 5.5V (T
A
= +25°C,
MAX1760ETB, MAX1760HETB)
V
LX
= V
OUT
= 5.5V, in shutdown (T
A
=
+25°C, MAX1760ETB, MAX1760HETB)
0.1
0.1
10
10
µA
µA
Rising edge (Note 4)
V
ISET
= 1.25V (T
A
= +25°C, MAX1760ETB,
MAX1760HETB)
V
ON
= 3.6V, V
ON
= 0V
CLK/SEL = GND (Note 5)
CLK/SEL = OUT
V
FB
< 0.1V, CLK/SEL = OUT, includes load
regulation for 0 < I
LX
< 0.55A
Adjustable output, CLK/SEL = OUT, includes
load regulation for 0 < I
LX
< 0.55A
V
FB
= 1.35V (T
A
= +25°C, MAX1760ETB,
MAX1760HETB)
CLK/SEL = OUT, no load to full load
(0 < I
LX
< 1.0A)
2.5
2.00
2.15
±0.01
0.1
100
2.5
(Note 1)
I
LOAD
< 1mA, T
A
= +25°C (Note 2)
I
LOAD
< 1mA
V
OUT
= 1.5V
CLK/SEL = OUT
(Note 3)
125
0.8
80
0.5
3.17
1.215
3.3
1.240
0.01
-1.5
5.5
2.30
±50
5
185
0.7
0.9
-2.3
500
1
86
1000
1.2
90
1.2
3.38
1.270
100
5.5
1.1
V
V
mV/°C
kHz
MHz
%
MHz
V
V
nA
%
V
V
nA
µA
µA
mA
CONDITIONS
MIN
TYP
MAX
UNITS
2
_______________________________________________________________________________________
0.8A, Low-Noise, 1MHz,
Step-Up DC-DC Converter
ELECTRICAL CHARACTERISTICS (continued)
(CLK/SEL = FB = PGND = GND, ISET = REF, OUT = POUT, V
OUT
= 3.6V,
T
A
= 0°C to +85°C.
Typical values are at T
A
= +25°C,
unless otherwise noted.)
PARAMETER
Switch On-Resistance
N-Channel Current Limit
P-Channel Turn-Off Current
REFERENCES
Reference Output Voltage
Reference Load Regulation
Reference Supply Rejection
LOGIC INPUTS
CLK/SEL Input Low Level
CLK/SEL Input High Level
ON,
ON
Input Low Level (Note 6)
2.5V
≤
V
OUT
≤
5.5V
2.5V
≤
V
OUT
≤
5.5V
1.1V
≤
V
OUT
≤
1.8V
1.8V
≤
V
OUT
≤
5.5V
1.1V
≤
V
OUT
≤
1.8V
1.8V
≤
V
OUT
≤
5.5V
Input Leakage Current
Minimum CLK/SEL Pulse Width
Maximum CLK/SEL Rise/Fall Time
CLK/SEL,
ON,
ON (T
A
= +25°C,
MAX1760ETB, MAX1760HETB)
V
OUT
- 0.2
1.6
0.01
200
100
1
µA
ns
ns
0.8 x
V
OUT
0.2
0.4
0.2 x
V
OUT
V
V
V
I
REF
= 0
-1µA < IREF < +50µA
2.5V < V
OUT
< 5V
1.230
1.250
5
0.2
1.270
15
5
V
mV
mV
CLK/SEL = GND
N-channel
P-channel
1.0
20
CONDITIONS
MIN
TYP
0.15
0.25
1.25
60
MAX
0.28
0.45
1.6
120
UNITS
Ω
A
mA
MAX1760/MAX1760H
ON,
ON
Input High Level (Note 6)
V
ELECTRICAL CHARACTERISTICS
(CLK/SEL = FB = PGND = GND, ISET = REF, OUT = POUT, V
OUT
= 3.6V,
T
A
= -40°C to +85°C,
unless otherwise noted.) (Note 7)
PARAMETER
DC-DC CONVERTER
Output Voltage
FB Regulation Voltage
Internal Oscillator Frequency
Oscillator Maximum Duty Cycle
Output Voltage Lockout Threshold
Supply Current in Shutdown
No-Load Supply Current
DC-DC SWITCHES
Switch On-Resistance
N-channel
P-channel
0.28
0.45
Ω
V
FB
< 0.1V, CLK/SEL = OUT, includes load
regulation for 0 < I
LX
< 0.55A
Adjustable output, CLK/SEL = OUT, includes
load regulation for 0 < I
LX
< 0.55A
CLK/SEL = OUT
(Note 3)
Rising edge (Note 4)
V
ON
= 3.6V
CLK/SEL = GND (Note 5)
3.17
1.215
0.75
80
2.00
3.38
1.270
1.2
90
2.30
5
185
V
V
MHz
%
V
µA
µA
CONDITIONS
MIN
MAX
UNITS
_______________________________________________________________________________________
3
0.8A, Low-Noise, 1MHz,
Step-Up DC-DC Converter
MAX1760/MAX1760H
ELECTRICAL CHARACTERISTICS (continued)
(CLK/SEL = FB = PGND = GND, ISET = REF, OUT = POUT, V
OUT
= 3.6V,
T
A
= -40°C to +85°C,
unless otherwise noted.) (Note 7)
PARAMETER
N-Channel Current Limit
REFERENCE
Reference Output Voltage
LOGIC INPUTS
CLK/SEL Input Low Level
CLK/SEL Input High Level
ON,
ON
Input Low Level (Note 6)
ON,
ON
Input High Level (Note 6)
Input Leakage Current
2.5V
≤
V
OUT
≤
5.5V
2.5V
≤
V
OUT
≤
5.5V
1.1V
≤
V
OUT
≤
1.8V
1.8V
≤
V
OUT
≤
5.5V
1.1V
≤
V
OUT
≤
1.8V
1.8V
≤
V
OUT
≤
5.5V
CLK/SEL,
ON,
ON
V
OUT
+ 0.2
1.6
1
0.8 x
V
OUT
0.2
0.4
0.2 x
V
OUT
V
V
V
V
µA
I
REF
= 0
1.230
1.270
V
CONDITIONS
MIN
1.0
MAX
1.6
UNITS
A
Note 1:
Operating voltage—since the regulator is bootstrapped to the output, once started, the MAX1760 operates down
to 0.7V input.
Note 2:
Startup is tested with the circuit shown in Figure 6.
Note 3:
Defines maximum step-up ratio.
Note 4:
The regulator is in startup mode until this voltage is reached. Do not apply full load current until the output exceeds 2.3V.
Note 5:
Supply current into 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.
Note 6:
ON
(MAX1760) and ON (MAX1760H) have a hysteresis of approximately 0.15
×
V
OUT
.
Note 7:
Specifications to -40°C are guaranteed by design and not production tested.
Typical Operating Characteristics
(Circuit of Figure 2, V
IN
= 2.4V, V
OUT
= 3.3V, T
A
= +25°C, unless otherwise noted.)
EFFICIENCY vs. OUTPUT CURRENT
V
OUT
= 3.3V
A
MAX1760 toc01
EFFICIENCY vs. OUTPUT CURRENT
V
OUT
= 5V
90
80
EFFICIENCY (%)
70
60
50
40
30
20
10
1
0
0.0001
0.001
= AUTO MODE
= FPWM MODE
A: V
IN
= 3.6V
B: V
IN
= 2.4V
C: V
IN
= 1.2V
0.01
0.1
1
C
B
A
MAX1760-02
MAXIMUM OUTPUT CURRENT
vs. INPUT VOLTAGE
0.8
OUTPUT CURRENT (A)
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.5
1.0
V
OUT
= 5V
V
OUT
= 3.3V
MAX1760-03
100
90
80
EFFICIENCY (%)
70
60
50
40
30
20
10
0
0.0001
0.001
C
100
0.9
B
= AUTO MODE
= FPWM MODE
A: V
IN
= 2.4V
B: V
IN
= 1.2V
C: V
IN
= 0.9V
0.01
0.1
OUTPUT CURRENT (A)
OUTPUT CURRENT (A)
1.5 2.0 2.5 3.0
INPUT VOLTAGE (V)
3.5
4.0
4
_______________________________________________________________________________________
0.8A, Low-Noise, 1MHz,
Step-Up DC-DC Converter
MAX1760/MAX1760H
Typical Operating Characteristics (continued)
(Circuit of Figure 2, V
IN
= 2.4V, V
OUT
= 3.3V, T
A
= +25°C, unless otherwise noted.)
NO-LOAD BATTERY CURRENT
vs. INPUT VOLTAGE
MAX1760-04
TOTAL SHUTDOWN CURRENT
(I
LX
+ I
OUT
) vs. INPUT VOLTAGE
MAX1760-05
INTERNAL OSCILLATOR
FREQUENCY vs. TEMPERATURE
1.15
1.10
FREQUENCY (MHz)
1.05
1.00
0.95
0.90
0.85
0.80
MAX1760-06
2.5
10
1.20
1.5
SHUTDOWN CURRENT (nA)
2.0
INPUT CURRENT (mA)
1
1.0
V
OUT
= 5V
V
OUT
= 3.3V
0.0
0
1
2
3
4
5
INPUT VOLTAGE (V)
0.5
0.1
0
1
2
3
4
5
6
INPUT VOLTAGE (V)
0.75
-40
-15
10
35
60
85
TEMPERATURE (°C)
STARTUP VOLTAGE
vs. OUTPUT CURRENT
MAX1760-07
PEAK INDUCTOR CURRENT vs. V
ISET
MAX1760-08
HEAVY-LOAD SWITCHING WAVEFORMS
MAX1760-09
3.0
2.5
STARTUP VOLTAGE (V)
2.0
PEAK INDUCTOR CURRENT (A)
A = +85°C
B = +25°C
C = -40°C
1.4
1.2
1.0
0.8
A
A
1.5
1.0
0.5
B
C
B
0.6
0.4
0.2
0.0
C
0V
0.1
0.3
0.5
0.7
V
ISET
(V)
0.9
1.1
1.3
A = LX PIN, 5V/div
B = INDUCTOR CURRENT, 200mA/div
C = OUTPUT RIPPLE, 50mV/div AC-COUPLED
t = 400ns/div
CIRCUIT OF FIGURE 6
0.0
0.001
0.01
0.1
1
OUTPUT CURRENT (A)
LIGHT-LOAD SWITCHING WAVEFORMS
MAX1760-10
LOAD-TRANSIENT RESPONSE
MAX1760-11
LINE-TRANSIENT RESPONSE
MAX1760-12
A
A
A
B
C
B
B
t = 400ns/div
A = LX PIN, 5V/div
B = INDUCTOR CURRENT, 200mA/div
C = OUTPUT RIPPLE, 50mV/div, AC-COUPLED
t = 200ms/div
V
IN
= 1.1V, V
OUT
= 3.3V, I
OUT
= 0 AND 0.2A
A = I
OUT
, 100mA/div
B = V
OUT
, 50mV/div, AC-COUPLED
400µs/div
V
IN
=
2.4V TO 1.4V, I
OUT
=
70mA
A = V
IN
, 1V/div
B = V
OUT
, 5mA/div, AC-COUPLED
_______________________________________________________________________________________
5
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