MAX1722/MAX1723/
MAX1724
1.5µA IQ, Step-Up DC-DC Converters in TSOT
General Description
The MAX1722/MAX1723/MAX1724 compact, high-efficiency, step-up DC-DC converters are available in tiny,
5-pin TSOT packages. They feature an extremely low
1.5µA quiescent supply current to ensure the highest possible light-load efficiency. Optimized for operation from
one to two alkaline or nickel-metal-hydride (NiMH) cells, or
a single Li+ cell, these devices are ideal for applications
where extremely low quiescent current and ultra-small size
are critical.
Built-in synchronous rectification significantly improves
efficiency and reduces size and cost by eliminating the
need for an external Schottky diode. All three devices feature a 0.5Ω N-channel power switch. The MAX1722/
MAX1724 also feature proprietary noise-reduction circuitry,
which suppresses electromagnetic interference (EMI)
caused by the inductor in many step-up applications. The
family offers different combinations of fixed or adjustable
outputs, shutdown, and EMI reduction (see Selector
Guide).
Features
o
o
o
o
o
o
o
o
o
o
o
Up to 90% Efficiency
No External Diode or FETs Needed
1.5µA Quiescent Supply Current
0.1µA Logic-Controlled Shutdown
±1% Output Voltage Accuracy
Fixed Output Voltage (MAX1724) or Adjustable
Output Voltage (MAX1722/MAX1723)
Up to 150mA Output Current
0.8V to 5.5V Input Voltage Range
0.91V Guaranteed Startup (MAX1722/MAX1724)
Internal EMI Suppression (MAX1722/MAX1724)
TSOT Package (0.9mm typ Height)
Ordering Information
PART
Applications
Pagers
Remote Controls
Single-Cell BatteryPowered Devices
Low-Power Hand-Held
Instruments
MP3 Players
Remote Wireless
Transmitters
Personal
Medical Devices
Digital Still Cameras
Personal Digital
Assistants (PDA)
TEMP RANGE
PINPACKAGE
TOP
MARK
MAX1722EZK+T+
-40°C to +85°C
5 TSOT
ADQF
MAX1723EZK+T
-40°C to +85°C
5 TSOT
ADQG
MAX1724EZK27+T
MAX1724EZK30+T
-40°C to +85°C
5 TSOT
ADQH
-40°C to +85°C
5 TSOT
ADQI
MAX1724EZK33+T
-40°C to +85°C
5 TSOT
ADQJ
MAX1724EZK50+T -40°C to +85°C 5 TSOT
+Denotes a lead(Pb)-free/RoHS-compliant package.
T = Tape and reel.
ADQK
Selector Guide appears at end of data sheet.
Typical Operating Circuit
Pin Configurations
TOP VIEW
10μH
+
BATT
IN
0.8V TO 5.5V
BATT
1
5
LX
4
OUT
LX
GND 2
MAX1724
MAX1722
OUT
OUT
ON
OFF
SHDN
GND
3.3V AT
UP TO 150mA
FB 3
TSOT
Pin Configurations are continued at end of data sheet.
For pricing, delivery, and ordering information, please contact Maxim Direct
at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.
19-1735; Rev 2; 5/13
MAX1722/MAX1723/MAX1724
1.5µA IQ, Step-Up DC-DC Converters in TSOT
ELECTRICAL CHARACTERISTICS (continued)
(VBATT = 1.2V, VOUT = 3.3V (MAX1722/MAX1723), VOUT = VOUT(NOM) (MAX1724), SHDN = OUT, RL = ∞, TA = 0°C to +85°C,
unless otherwise noted. Typical values are at TA = +25°C.) (Note 1)
PARAMETER
SYMBOL
Shutdown Current into BATT
SHDN Voltage Threshold
CONDITIONS
MAX1724 (Note 4)
VIL
MAX
0.001
0.5
TA = +85°C
0.01
MIN
75
MAX1723/MAX1724
VIH
TYP
TA = +25°C
MAX1723/MAX1724
MAX1723/MAX1724,
V SHDN = 5.5V
SHDN Input Bias Current
400
500
800
TA = +25°C
2
100
TA = +85°C
7
UNITS
µA
mV
nA
ELECTRICAL CHARACTERISTICS
(VBATT = 1.2V, VOUT = 3.3V (MAX1722/MAX1723), VOUT = VOUT(NOM) (MAX1724), SHDN = OUT, RL = ∞, TA = -40°C to +85°C,
unless otherwise noted.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
MAX1724EZK27
2.633
2.767
MAX1724EZK30
2.925
3.075
MAX1724EZK33
3.218
3.383
MAX1724EZK50
UNITS
Output Voltage
VOUT
4.875
5.125
Output Voltage Range
VOUT
MAX1722/MAX1723
2
5.5
1.200
V
Feedback Voltage
V
VFB
MAX1722/MAX1723
1.270
V
N-Channel On-Resistance
RDS(ON)
VOUT forced to 3.3V
1.0
Ω
P-Channel On-Resistance
RDS(ON)
VOUT forced to 3.3V
2.0
Ω
N-Channel Switch Current Limit
ILIM
VOUT forced to 3.3V
400
620
mA
Switch Maximum On-Time
tON
3.5
6.5
µs
5
35
mA
3.6
µA
Synchronous Rectifier ZeroCrossing Current
VOUT forced to 3.3V
Quiescent Current into OUT
(Notes 3,4)
SHDN Voltage Threshold
VIL
MAX1723/MAX1724
VIH
MAX1723/MAX1724
75
800
mV
Note 1: Limits are 100% production tested at TA = +25°C. Limits over the operating temperature range are guaranteed by design.
Note 2: Guaranteed with the addition of a Schottky MBR0520L external diode between LX and OUT when using the MAX1723
with only one cell, and assumes a 0.3V voltage drop across the Schottky diode (see Figure 3).
Note 3: Supply current is measured with an ammeter between the output and OUT pin. This current correlates directly with actual
battery supply current, but is reduced in value according to the step-up ratio and efficiency.
Note 4: VOUT forced to the following conditions to inhibit switching: VOUT = 1.05 VOUT(NOM) (MAX1724), VOUT = 3.465V
(MAX1722/MAX1723).
Maxim Integrated
3
