Rainbow Electronics MAX1706 - Manual (Page 7)

MAX1705/MAX1706
1- to 3-Cell, High-Current, Low-Noise,
Step-Up DC-DC Converters with Linear Regulator
_______________________________________________________________________________________ 7
____________________________Typical Operating Characteristics (continued)
(Circuit of Figure 2, T
A
= +25°C, unless otherwise noted.)
60
0
100 10k 100k 1M 1k 10M
LINEAR-REGULATOR POWER-SUPPLY
REJECTION RATIO vs. FREQUENCY
10
20
MAX1705/6 TOC10
FREQUENCY (Hz)
PSRR (dB)
30
50
40
V OUT = 4V TO 5V
V LDO = 3.3V
I
LDO
= 200mA
C5 = 0.33 µ F
100
0
1 100 50 200 250 150 300
LINEAR-REGULATOR
REGION OF STABLE C6 ESR
vs. LOAD CURRENT
0.1
MAX1705/6 TOC11
LOAD CURRENT (mA)
C6 ESR (
Ω
)
1
10
STABLE REGION
C2 = 22pF (FEED FORWARD)
UNCOMPENSATED
C6 = 22 µ F
1k 10k 100k 1M 10M
MAX1705
NOISE SPECTRUM AT POUT
(V OUT = 4.5V, V IN = 1.2V, 200mA LOAD)
0V
MAX1705/6 TOC13
FREQUENCY (Hz)
NOISE (5mV
RMS/
div)
1k 10k 100k 1M 10M
MAX1705
LINEAR-REGULATOR OUTPUT NOISE SPECTRUM
(V LDO = 3.3V, V OUT = 4.5V, V IN = 1.2V, I LDO = 200mA)
0V
MAX1705/6 TOC14
FREQUENCY (Hz)
NOISE (50
µ
V/div)