19-1698; Rev 2; 4/11
KIT
ATION
EVALU
BLE
AVAILA
1.5A, Low-Noise, 1MHz, Step-Up
DC-DC Converter
General Description
Features
♦
Up to 94% Efficiency
♦
+0.7V to +5.5V Input Voltage Range
♦
1.1V Guaranteed Startup Input Voltage
♦
♦
♦
♦
♦
Up to 1.5A Output
Fixed 3.3V Output or Adjustable (2.5V to 5.5V)
1MHz PWM Synchronous-Rectified Topology
1µA Logic-Controlled Shutdown
Analog Gain Block for Linear-Regulator or Low-
Battery Comparator
♦
Adjustable Current Limit and Soft-Start
♦
1.5W TSSOP Package Available
Idle Mode is a trademark of Maxim Integrated Products.
MAX1763
The MAX1763 is a high-efficiency, low-noise, step-up
DC-DC converter intended for use in battery-powered
wireless applications. This device maintains exception-
ally low quiescent supply current (110µA) despite its
high 1MHz operating frequency. Small external compo-
nents and a tiny package make this device an excellent
choice for small hand-held applications that require the
longest possible battery life.
The MAX1763 uses a synchronous-rectified pulse-
width-modulation (PWM) boost topology to generate
2.5V to 5.5V outputs from a wide range of input
sources, such as one to three alkaline or NiCd/NiMH
cells or a single Lithium-ion (Li+) cell. Maxim's propri-
etary Idle Mode™ circuitry significantly improves effi-
ciency at light load currents while smoothly transitioning
to fixed-frequency PWM operation at higher load cur-
rents to maintain excellent full-load efficiency. Low-
noise, forced-PWM mode is available for applications
that require constant-frequency operation at all load
currents. The MAX1763 may also be synchronized to
an external clock to protect sensitive frequency bands
in communications equipment.
The MAX1763 includes an on-chip linear gain block
that can be used to build a high-power external linear
regulator or as a low-battery comparator. Soft-start and
current limit functions permit optimization of efficiency,
external component size, and output voltage ripple.
The MAX1763 is available in a space-saving 16-pin
QSOP package or a high-power (1.5W) 16-pin TSSOP-
EP package.
________________________Applications
Digital Cordless
Phones
PCS Phones
Wireless Handsets
Hand-Held
Instruments
Palmtop Computers
Personal
Communicators
Ordering Information
PART
MAX1763EEE+
MAX1763EUE+
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
16 QSOP
16 TSSOP-EP*
Typical Operating Circuit
IN
0.7V TO 5.5V
1.5μH
+Denotes
a lead(Pb)-free/RoHS-compliant package.
*EP
= Exposed pad
Pin Configuration
LX
POUT
OUT
3.3V AT 1.5A
TOP VIEW
ONA 1
ISET 2
16 ONB
15 POUT
14 LX
OFF
ON
PWM
OR NORMAL
MAX1763
ON
OFF
ONB
ONA
CLK/SEL
AIN
ISET
REF
FB
GND
AO
PGND
LBO OR
GAIN BLOCK OUTPUT
OUT
REF 3
GND 4
FB 5
OUT 6
AIN 7
AO 8
MAX1763
13 POUT
12 PGND
11 LX
10 PGND
9
CLK/SEL
LBI OR GAIN
BLOCK INPUT
QSOP
TSSOP-EP
________________________________________________________________
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.
1.5A, Low-Noise, 1MHz, Step-Up
DC-DC Converter
MAX1763
ABSOLUTE MAXIMUM RATINGS
ONA,
ONB,
AO, OUT to GND.......................................0.3V, +6V
PGND to GND.....................................................................±0.3V
LX to PGND ............................................-0.3V to (V
POUT
+ 0.3V)
CLK/SEL, REF, FB, ISET, POUT,
AIN to GND.........................................-0.3V to (V
OUT
+ 0.3V)
POUT to OUT ......................................................................±0.3V
Continuous Power Dissipation
16-Pin QSOP (derate 8.7mW/°C above +70°C)...........667mW
16-Pin TSSOP-EP (derate 19mW/°C above +70°C) ...........1.5W
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
Soldering Temperature (reflow) .......................................+260°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 =
ONB
= FB = PGND = GND, ISET = REF, OUT = POUT, V
ONA
= V
AIN
= V
OUT
= 3.6V,
T
A
= 0°C to +85°C,
unless other-
wise noted. Typical values are at T
A
= +25°C.)
PARAMETER
DC-DC CONVERTER
Input Voltage Range (Note 1)
Minimum Startup Voltage
(Note 2)
Temperature Coefficient of
Startup Voltage
Frequency in Startup Mode
Internal Oscillator Frequency
Oscillator Maximum Duty Cycle
(Note 3)
External Clock Frequency Range
Output Voltage
FB Regulation Voltage
FB Input Current
Load Regulation
Output Voltage Adjust Range
Output Voltage Lockout
Threshold (Note 4)
ISET Input Leakage Current
Supply Current in Shutdown
No-Load Supply Current, Low-
Power Mode (Note 5)
No-Load Supply Current, Low-
Noise Mode
Gain Block Supply Current
Rising edge
V
ISET
= 1.25V
V
ONB
= 3.6V, V
ONA
= 0V
CLK/SEL = GND, AIN = OUT
CLK/SEL = OUT
V
AIN
< (V
OUT
- 1.4V), gain block enabled
V
FB
< 0.1V, CLK/SEL = OUT, includes load regulation
for 0 < I
LX
< 1.1A
Adjustable output, CLK/SEL = OUT, includes load
regulation for 0 < I
LX
< 1.1A
V
FB
= 1.35V
CLK/SEL = OUT, 0 < I
LX
< 1.1A
2.5
2.00
2.15
0.01
1
110
2.5
25
50
I
LOAD
< 1mA, T
A
= +25°C
I
LOAD
< 1mA
V
OUT
= 1.5V
CLK/SEL = OUT
125
0.8
80
0.5
3.17
1.215
3.3
1.245
0.01
-1.0
5.5
2.30
50
10
200
0.7
0.9
-2
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
µA
CONDITIONS
MIN
TYP
MAX
UNITS
2
_______________________________________________________________________________________
1.5A, Low-Noise, 1MHz, Step-Up
DC-DC Converter
ELECTRICAL CHARACTERISTICS (continued)
(CLK/SEL =
ONB
= FB = PGND = GND, ISET = REF, OUT = POUT, V
ONA
= V
AIN
= V
OUT
= 3.6V,
T
A
= 0°C to +85°C,
unless other-
wise noted. Typical values are at T
A
= +25°C.)
PARAMETER
DC-DC SWITCHES
POUT Leakage Current
LX Leakage Current
Switch On-Resistance
N-Channel Current Limit
P-Channel Turn-Off Current
REFERENCE
Reference Output Voltage
Reference Load Regulation
Reference Supply Rejection
GAIN BLOCK
AIN Reference Voltage
AIN Input Current
Transconductance
AO Output Low Voltage
AO Output High Leakage
Gain-Block Enable Threshold
(V
OUT
- V
AIN
) (Note 6)
Gain-Block Disable Threshold
(V
OUT
- V
AIN
) (Note 6)
LOGIC INPUTS
CLK/SEL Input Low Level
CLK/SEL Input High Level
ONA and
ONB
Input Low Level
(Note 7)
ONA and
ONB
Input High Level
(Note 7)
Input Leakage Current
Minimum CLK/SEL Pulse Width
Maximum CLK/SEL
Rise/Fall Time
2.5V
≤
V
OUT
≤
5.5V
2.5 V
≤
V
OUT
≤
5.5V
1.1 V
≤
V
OUT
≤
1.8V
1.8 V
≤
V
OUT
≤
5.5V
1.1 V
≤
V
OUT
≤
1.8V
1.8 V
≤
V
OUT
≤
5.5V
CLK/SEL, ONA,
ONB
V
OUT
- 0.2V
1.6
0.01
100
100
1
µA
ns
ns
(0.8)
V
OUT
0.2
0.4
(0.2)
V
OUT
V
V
V
0.2
I
AO
= 20µA
V
AIN
= 1.5V
V
AO
= 1V, 10µA < I
AO
< 100µA
V
AIN
= 0.5V, I
AO
= 100µA
V
AIN
= 1.5V, V
AO
= 5.5V
5
910
938
±0.01
10
0.1
0.01
970
±30
16
0.4
1
1.4
mV
nA
mS
V
µA
V
V
I
REF
= 0A
-1µA < I
REF
< 50µA
2.5V < V
OUT
< 5V
1.230
1.250
5
0.2
1.270
15
5
V
mV
mV
CLK/SEL = GND
V
LX
= 0V, V
OUT
= 5.5V
V
LX
= V
ONB
= V
OUT
= 5.5V, V
ONA
= 0V
N channel
P channel
2.0
10
0.1
0.1
0.075
0.13
2.5
120
10
10
0.13
0.25
3.4
240
µA
µA
Ω
A
mA
CONDITIONS
MIN
TYP
MAX
UNITS
MAX1763
V
_______________________________________________________________________________________
3
1.5A, Low-Noise, 1MHz, Step-Up
DC-DC Converter
MAX1763
ELECTRICAL CHARACTERISTICS
(CLK/SEL =
ONB
= FB = PGND = GND, ISET = REF, OUT = POUT, V
ONA
= V
AIN
= V
OUT
= 3.6V,
T
A
= -40°C to +85°C,
unless other-
wise noted.) (Note 8)
PARAMETER
DC-DC CONVERTER
Input Voltage Range (Note 1)
Minimum Startup Voltage (Note 2)
Frequency in Startup Mode
Internal Oscillator Frequency
Oscillator Maximum Duty Cycle
(Note 3)
External Clock Frequency Range
Output Voltage
FB Regulation Voltage
FB Input Current
Output Voltage Adjust Range
Output Voltage Lockout
Threshold (Note 4)
ISET Input Leakage Current
Supply Current in Shutdown
No-Load Supply Current, Low-
Power Mode (Note 5)
Gain Block Supply Current
DC-DC SWITCHES
POUT Leakage Current
LX Leakage Current
Switch On-Resistance
N-Channel Current Limit
P-Channel Turn-Off Current
REFERENCE
Reference Output Voltage
Reference Load Regulation
Reference Supply Rejection
GAIN BLOCK
AIN Reference Voltage
AIN Input Current
Transconductance
AO Output Low Voltage
AO Output High Leakage
I
AO
= 20µA
V
AIN
= 1.5V
V
AO
= 1V, 10µA < I
AO
< 100µA
V
AIN
= 0.5V, I
AO
= 100µA
V
AIN
= 1.5V, V
AO
= 5.5V
5
910
970
±30
16
0.4
1
mV
nA
mS
V
µA
I
REF
= 0A
-1µA < I
REF
< 50µA
2.5V < V
OUT
< 5V
1.220
1.270
15
5
V
mV
mV
CLK/SEL = GND
V
LX
= 0V, V
OUT
= 5.5V
V
LX
= V
ONB
= V
OUT
= 5.5V, V
ONA
= 0V
N-channel
P-channel
2.0
10
10
10
0.13
0.25
3.4
240
µA
µA
Ω
A
mA
Rising edge
V
ISET
= 1.25V
V
ONB
= 3.6V, V
ONA
= 0V
CLK/SEL = GND, AIN = OUT
V
AIN
< (V
OUT
- 1.4V), gain block enabled
V
FB
< 0.1V, CLK/SEL = OUT, includes load regulation
for 0 < I
LX
< 1.1A
Adjustable output, CLK/SEL = OUT, includes load
regulation for 0 < I
LX
< 1.1A
V
FB
= 1.35V
2.5
2.00
I
LOAD
< 1mA, T
A
= +25°C
V
OUT
= 1.5V
CLK/SEL = OUT
125
0.75
80
0.6
3.17
1.215
5.5
1.1
1000
1.25
91
1.2
3.38
1.270
100
5.5
2.30
50
10
200
50
V
V
kHz
MHz
%
MHz
V
V
nA
V
V
nA
µA
µA
µA
CONDITIONS
MIN
MAX
UNITS
4
_______________________________________________________________________________________
1.5A, Low-Noise, 1MHz, Step-Up
DC-DC Converter
ELECTRICAL CHARACTERISTICS (continued)
(CLK/SEL =
ONB
= FB = PGND = GND, ISET = REF, OUT = POUT, V
ONA
= V
AIN
= V
OUT
= 3.6V,
T
A
= -40°C to +85°C,
unless other-
wise noted.) (Note 8)
PARAMETER
LOGIC INPUTS
Gain-Block Enable Threshold
(V
OUT
- V
AIN
) (Note 6)
Gain-Block Disable Threshold
(V
OUT
- V
AIN
) (Note 6)
CLK/SEL Input Low Level
CLK/SEL Input High Level
ONA and
ONB
Input Low Level
(Note 7)
ONA and
ONB
Input High Level
(Note 7)
Input Leakage Current
2.5 V
≤
V
OUT
≤
5.5V
2.5 V
≤
V
OUT
≤
5.5V
1.1 V
≤
V
OUT
≤
1.8V
1.8 V
≤
V
OUT
≤
5.5V
1.1 V
≤
V
OUT
≤
1.8V
1.8V
≤
V
OUT
≤
5.5V
CLK/SEL, ONA,
ONB
V
OUT
- 0.2V
1.6
1
µA
(0.8)
V
OUT
0.2
0.4
0.2
(0.2)
V
OUT
1.4
V
V
V
V
V
CONDITIONS
MIN
MAX
UNITS
MAX1763
V
Note 1:
Operating voltage. Because the regulator is bootstrapped to the output, once started, the MAX1763 will operate down to
0.7V input. For conditions where V
IN
might exceed the set V
OUT
, or where V
OUT
is set above 4V, an external Schottky diode
must be connected from LX to POUT.
Note 2:
Startup is tested with the circuit of Figure 2.
Note 3:
Defines low-noise mode 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 from the 3.3V output is measured between the 3.3V 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. The gain block is
disabled.
Note 6:
Connect AIN to OUT to disable gain block.
Note 7:
ONA and
ONB
have hysteresis of approximately 0.15
✕
V
OUT
.
Note 8:
Specifications to -40°C are guaranteed by design and not production tested.
_______________________________________________________________________________________
5