Typical operating characteristics (continued) – Rainbow Electronics MAX1721 User Manual
Page 4
0
150
100
50
200
250
300
350
400
450
500
0
10
5
15
20
25
30
MAX1720
OUTPUT VOLTAGE RIPPLE
vs. CAPACITANCE
MAX1720/21toc12
CAPACITANCE (
µ
F)
OUTPUT VOLTAGE RIPPLE (mVp-p)
V
IN
= +4.75V, V
OUT
= -4.0V
V
IN
= +3.15V, V
OUT
= -2.5V
V
IN
= +1.9V, V
OUT
= -1.5V
0
10
5
20
15
30
25
35
0
20
10
30
40
5
25
15
35
45 50
MAX1720
OUTPUT CURRENT vs. CAPACITANCE
MAX1720/21toc11
CAPACITANCE (
µ
F)
OUTPUT CURRENT (mA)
V
IN
= +1.9V, V
OUT
= -1.5V
V
IN
= +3.15V, V
OUT
= -2.5V
V
IN
= +4.75V, V
OUT
= -4.0V
MAX1719/MAX1720/MAX1721
SOT23, Switched-Capacitor
Voltage Inverters with Shutdown
4
_______________________________________________________________________________________
500
µ
s/div
MAX1720
START-UP FROM SHUTDOWN
R
L
= 1k
Ω
V
OUT
2V/div
MAX1720/21toc10
V
SHDN
5V/div
10
20
40
30
60
70
50
80
1.5
2.5
3.0
2.0
3.5
4.0
4.5
5.0
5.5
OUTPUT RESISTANCE
vs. INPUT VOLTAGE
MAX1720/21toc04
INPUT VOLTAGE (V)
OUTPUT RESISTANCE (
Ω
)
MAX1720
MAX1719/
MAX1721
10
30
20
50
40
60
70
-40
10
-15
35
60
85
OUTPUT RESISTANCE
vs. TEMPERATURE
MAX1720/21toc07
TEMPERATURE (°C)
OUTPUT RESISTANCE (
Ω
)
V
IN
= +2V
V
IN
= +1.5V
V
IN
= +3.3V
V
IN
= +5V
0
100
50
250
200
150
400
350
300
450
1.5
3.0
3.5
2.0
2.5
4.0
4.5
5.0
5.5
SUPPLY CURRENT
vs. INPUT VOLTAGE
MAX1720/21toc05
INPUT VOLTAGE (V)
SUPPLY CURRENT (
µ
A)
MAX1720
MAX1719/
MAX1721
+85°C
+85°C
-40°C
-40°C
0
10
5
20
15
25
30
-40
10
-15
35
60
85
SHUTDOWN SUPPLY CURRENT
vs. TEMPERATURE
MAX1720/21toc06
TEMPERATURE (°C)
SHUTDOWN SUPPLY CURRENT (nA)
V
IN
= +5V
V
IN
= +3.3V
V
IN
= +1.5V
1000
10
-40
35
60
-15
-10
85
PUMP FREQUENCY
vs. TEMPERATURE
100
MAX1720/21toc08
TEMPERATURE (°C)
FREQUENCY (kHz)
MAX1719/MAX1721
V
IN
= +5V
V
IN
= +1.5V
MAX1720
V
IN
= +1.5V
V
IN
= +5V
10
µ
s/div
OUTPUT NOISE AND RIPPLE
V
IN
= 3.3V, V
OUT
= -3.17V, I
OUT
= 5mA
20mV/div, AC-COUPLED
V
OUT
MAX1721
V
OUT
MAX1720
MAX1720/21toc09
Typical Operating Characteristics (continued)
(Circuit of Figure 1, V
IN
= +5V, SHDN = GND (MAX1719), SHDN = IN (MAX1720/MAX1721), C1 = C2 = C3, T
A
= +25°C, unless oth-
erwise noted.)