Typical operating characteristics (continued) – Rainbow Electronics MAX868 User Manual
Page 4
MAX868
Regulated, Adjustable -2x
Inverting Charge Pump
4
_______________________________________________________________________________________
____________________________Typical Operating Characteristics (continued)
(Circuit of Figure 5, T
A
= +25°C, unless otherwise noted.)
0
0.01
1
0.1
10
100
EFFICIENCY vs. LOAD CURRENT
(V
IN
= 5V)
10
MAX868-04
LOAD CURRENT (mA)
EFFICIENCY (%)
50
40
30
20
60
70
80
V
OUT
= -5V
V
OUT
= -7.5V
V
OUT
= -3.3V
0
0.01
1
0.1
10
100
EFFICIENCY vs. LOAD CURRENT
(V
IN
= 3.3V)
10
MAX868-05
LOAD CURRENT (mA)
EFFICIENCY (%)
50
40
30
20
60
70
80
V
OUT
= -5V
V
OUT
= -3.3V
0
0.01
1
0.1
10
100
EFFICIENCY vs. LOAD CURRENT
(V
IN
= 5V)
10
MAX868-06
LOAD CURRENT (mA)
EFFICIENCY (%)
50
40
30
20
60
70
80
CIRCUIT OF FIGURE 6
V
OUT
= -2.5V
V
OUT
= -3.3V
0
60
40
20
100
80
180
160
140
120
200
-40
-20
0
20
40
60
80
100
OPEN-LOOP OUTPUT IMPEDANCE
vs. TEMPERATURE
(FB = IN, V
OUT
= -2 x V
IN
)
MAX868-07
TEMPERATURE (°C)
OUTPUT IMPEDANCE (
Ω
)
V
IN
= 2V
V
IN
= 3.3V
V
IN
= 5V
20
µ
s/div
20mV/div
V
IN
= 3.3V, V
OUT
= -3.3V, I
LOAD
= 5mA,
V
OUT
AC COUPLED (20mV/div), C
OUT
= 10
µ
F CERAMIC
OUTPUT VOLTAGE RIPPLE
(C
OUT
= 10
µ
F CERAMIC)
MAX868-10
0
60
40
20
100
80
180
160
140
120
200
-40
-20
0
20
40
60
80
100
OPEN-LOOP OUTPUT IMPEDANCE
vs. TEMPERATURE
(FB = IN, V
OUT
= -V
IN
)
MAX868-08
TEMPERATURE (°C)
OUTPUT IMPEDANCE (
Ω
)
V
IN
= 2V
CIRCUIT OF FIGURE 6
V
IN
= 3.3V
V
IN
= 5V
20
µ
s/div
20mV/div
V
IN
= 3.3V, V
OUT
= -3.3V, I
LOAD
= 5mA,
V
OUT
AC COUPLED (20mV/div), C
OUT
= 10
µ
F (AVX TPS)
OUTPUT VOLTAGE RIPPLE
(C
OUT
= 10
µ
F TANTALUM)
MAX868-09
20
µ
s/div
20mV/div
V
IN
= 3.3V, V
OUT
= -3.3V, I
LOAD
= 5mA,
V
OUT
AC COUPLED (20mV/div), C
OUT
= 2.2
µ
F CERAMIC
OUTPUT VOLTAGE RIPPLE
MAX868-11
200
µ
s/div
10mA/div
20mV/div
V
IN
= 5V, V
OUT
= -5V, I
OUT
= 1mA TO 11mA STEP
LOAD-TRANSIENT RESPONSE
MAX868-12