Datasheet

MAX1719/MAX1720/MAX1721
SOT23, Switched-Capacitor
Voltage Inverters with Shutdown
_______________________________________________________________________________________ 3
-5
-4
-3
-2
-1
0
0202510 1553035404550
OUTPUT VOLTAGE
vs. OUTPUT CURRENT
MAX1720/21toc01
OUTPUT CURRENT (mA)
OUTPUT VOLTAGE (V)
V
IN
= +1.5V
V
IN
= +2V
V
IN
= +3.3V
V
IN
= +5V
0
20
10
40
30
60
50
70
90
80
100
01015205253035 4540 50
MAX1720
EFFICIENCY vs. OUTPUT CURRENT
MAX1720/21toc02
OUTPUT CURRENT (mA)
EFFICIENCY (%)
V
IN
= +1.5V
V
IN
= +3.3V
V
IN
= +2V
V
IN
= +5V
0
20
10
40
30
60
50
70
90
80
100
01015205253035 4540 50
MAX1719/MAX1721
EFFICIENCY vs. OUTPUT CURRENT
MAX1720/21toc03
OUTPUT CURRENT (mA)
EFFICIENCY (%)
V
IN
= +1.5V
V
IN
= +2V
V
IN
= +3.3V
V
IN
= +5V
Typical Operating Characteristics
(Circuit of Figure 1, V
IN
= +5V, SHDN = GND (MAX1719), SHDN = IN (MAX1720/MAX1721), C1 = C2 = C3, T
A
= +25°C, unless other-
wise noted.)
ELECTRICAL CHARACTERISTICS
(V
IN
= +5V, SHDN = GND (MAX1719), SHDN = IN (MAX1720/MAX1721), C1 = C2 = 10µF (MAX1720), C1 = C2 = 1µF
(MAX1719/MAX1721), circuit of Figure 1, T
A
= -40°C to +85°C, unless otherwise noted.) (Note 2)
V
IN (MIN)
≤ V
IN
≤ +2.5V
R
L
= 10kΩ
+2.5V ≤ V
IN
≤ +5.5V
V
IN (MIN)
≤ V
IN
≤ +2.5V
+2.5V ≤ V
IN
≤ +5.5V
I
OUT
= 0
SHDN = IN (MAX1719), SHDN = GND
(MAX1720/MAX1721), OUT is internally
forced to GND in shutdown
MAX1720
I
OUT
= 10mA
CONDITIONS
0.2
V
0.6
V
IL
SHDN/ SHDN Input Logic Low
V
IN
- 0.2
V
2.1
V
IH
SHDN/ SHDN Input Logic High
Ω12R
O
,
SHDN
OUT to GND Shutdown
Resistance
65 ΩR
O
Output Resistance (Note 1)
MAX1719/MAX1721
1.6 5.5MAX1719/MAX1721
1.5 5.5MAX1720
%
99Voltage Conversion Efficiency
60 200
kHz
621
f
OSC
Oscillator Frequency
µA
100
I
CC
Quiescent Current (Note 3)
750
UNITSMIN TYP MAXSYMBOLPARAMETER
VV
IN
Supply Voltage Range
MAX1720
Note 1: Capacitor contribution (ESR component plus (1/f
OSC
) · C) is approximately 20% of output impedance.
Note 2: All specifications from -40°C to +85°C are guaranteed by design, not production tested.
Note 3: The MAX1719/MAX1720/MAX1721 may draw high supply current during startup, up to the minimum operating supply voltage.
To guarantee proper startup, the input supply must be capable of delivering 90mA more than the maximum load current.
Continuous, long-term
25 mA
RMS
I
OUT
Output Current
MAX1719/MAX1721