MAX1705 Maxim, MAX1705 Datasheet - Page 7

• Manufacturer Part Number: MAX1705
• Description: 1- to 3-Cell / High-Current / Low-Noise / Step-Up DC-DC Converters with Linear Regulator
• Manufacturer: Maxim

Step-Up DC-DC Converters with Linear Regulator
____________________________Typical Operating Characteristics (continued)
(Circuit of Figure 2, T
60
50
40
30
20
10
0
100
LINEAR-REGULATOR POWER-SUPPLY
REJECTION RATIO vs. FREQUENCY
_______________________________________________________________________________________
A
= +25°C, unless otherwise noted.)
1k
FREQUENCY (Hz)
10k
1- to 3-Cell, High-Current, Low-Noise,
0V
0V
1k
1k
100k
V
V
I
C5 = 0.33 F
LDO
OUT
LDO
= 200mA
= 4V TO 5V
= 3.3V
1M
(V
LDO
10M
LINEAR-REGULATOR OUTPUT NOISE SPECTRUM
10k
10k
= 3.3V, V
(V
OUT
NOISE SPECTRUM AT POUT
= 4.5V, V
OUT
FREQUENCY (Hz)
FREQUENCY (Hz)
= 4.5V, V
MAX1705
MAX1705
IN
100k
100k
= 1.2V, 200mA LOAD)
IN
= 1.2V, I
100
0.1
10
1
0
LDO
1
1M
1M
= 200mA)
STABLE REGION
50
REGION OF STABLE C6 ESR
LINEAR-REGULATOR
vs. LOAD CURRENT
LOAD CURRENT (mA)
100
C2 = 22pF (FEED FORWARD)
150
10M
10M
UNCOMPENSATED
200
C6 = 22 F
250
300
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