Typical operating characteristics (continued) – Rainbow Electronics MAX863 User Manual
Page 4
MAX863
Dual, High-Efficiency, PFM, Step-Up
DC-DC Controller
4
_______________________________________________________________________________________
____________________________Typical Operating Characteristics (continued)
(T
A
= +25°C, unless otherwise noted.)
0.01
0.1
10
20
30
40
50
60
70
80
90
100
0
1
10
100
1000
EFFICIENCY vs. OUTPUT CURRENT
(V
OUT1
= 12V, NON-BOOTSTRAPPED)
MAX863 toc04
OUTPUT CURRENT (mA)
EFFICIENCY (%)
V
OUT1
= 5.0V
A: V
IN
= 2.7V
B: V
IN
= 3.3V
C: V
IN
= 3.6V
D: V
IN
= 4.0V
E: V
IN
= 6.0V
A
B
C
D
E
3.5
1
1
10
1000
BOOTSTRAPPED-MODE MINIMUM
START-UP INPUT VOLTAGE
vs. OUTPUT CURRENT
0.5
1.0
1.5
2.0
2.5
3.0
MAX863toc05
OUTPUT CURRENT (mA)
START-UP INPUT VOLTAGE (V)
100
V
OUT1
= 3.3V
V
OUT1
= 5V
0
0
12
V
DD
CURRENT
vs. V
DD
VOLTAGE
10
20
60
MAX863 toc15
V
DD
VOLTAGE (V)
V
DD
CURRENT (
µ
A)
40
30
8
50
10
2
4
6
Cond: Single +5V
BOTH ON
CONVERTER 1 ON
CONVERTER 2 ON
LOAD-TRANSIENT RESPONSE
A
MAX863 toc08
B
100
µs/div
V
OUT1
= 3.3V, I
OUT1
= 100mA TO 600mA
A: V
OUT1
, 100mV/div, 3.3V DC OFFSET
B: I
OUT1
, 200mA/div
RESPONSE ENTERING/
EXITING SHUTDOWN (BOOTSTRAPPED)
B
A
MAX863 toc09
C
3.3V
200
µs/div
V
OUT1
= 3.3V, I
OUT1
= 100mA, V
IN
= 2.4V
A: SHDN1, 5V/div
B: INDUCTOR CURRENT, 2A/div
C: V
OUT1
, 3.3V OFFSET, 500mV/div
LINE-TRANSIENT RESPONSE
B
A
MAX863 toc10
C
0A
500
µs/div
V
OUT1
= 5V, I
OUT1
= 800mA
A: V
IN
= 2.7V TO 3.7V, 500mV/div
B: V
OUT1
, AC COUPLED, 50mV/div
C: INDUCTOR CURRENT, 2A/div
0
0
12
EXT RISE AND FALL TIMES vs.
SUPPLY VOLTAGE AND MOSFET CAPACITANCE
20
140
MAX863 toc07
SUPPLY VOLTAGE (V)
RISE/FALL TIME (ns)
6
60
80
40
2
4
8
120
100
C,1
C,2
B,1
B,2
A,1
A,2
10
Cond Single 5V
A: 470pF
B: 1.0nF
C: 2.2nF
1: RISE
2: FALL