Bypass fet for wcdma and cdmaone handsets, Typical operating characteristics – Rainbow Electronics MAX8508 User Manual
Page 4
MAX8506/MAX8507/MAX8508
PWM Step-Down DC-DC Converters with 75m
Ω
Bypass FET for WCDMA and cdmaOne Handsets
4
_______________________________________________________________________________________
Typical Operating Characteristics
(V
BATT
= V
BATTP
= 3.6V, SHDN = SKIP = BATT, HP = GND, T
A
= +25°C, unless otherwise noted.) (See the Typical Application Circuits.)
EFFICIENCY vs. OUTPUT VOLTAGE
IN NORMAL MODE
MAX8506 toc01
OUTPUT VOLTAGE (V)
EFFICIENCY (%)
3.0
2.5
2.0
1.5
1.0
0.5
60
70
80
90
100
50
0
3.5
R
LOAD
= 15Ω
R
LOAD
= 10Ω
R
LOAD
= 5Ω
SKIP = GND
EFFICIENCY vs. OUTPUT VOLTAGE
IN PWM MODE
MAX8506 toc02
OUTPUT VOLTAGE (V)
EFFICIENCY (%)
3.0
2.5
2.0
1.5
1.0
0.5
60
70
80
90
100
50
0
3.5
R
LOAD
= 15Ω
R
LOAD
= 10Ω
R
LOAD
= 5Ω
EFFICIENCY vs. INPUT VOLTAGE
5.0
4.5
4.0
3.5
3.0
2.5
5.5
MAX8506 toc03
INPUT VOLTAGE (V)
EFFICIENCY (%)
60
70
80
90
100
50
V
OUT
= 0.4V
V
OUT
= 1.2V
V
OUT
= 3.4V
SKIP = GND
R
LOAD
= 10Ω
LOAD CURRENT (mA)
100
10
1
1000
EFFICIENCY vs. LOAD CURRENT
MAX8506 toc04
EFFICIENCY (%)
60
70
80
90
100
50
V
OUT
= 2.5V;
NORMAL MODE
V
OUT
= 2.5V;
PWM
V
OUT
= 1.2V;
NORMAL MODE
V
OUT
= 1.2V;
PWM
DROPOUT VOLTAGE vs. LOAD CURRENT
MAX8506 toc05
LOAD CURRENT (mA)
OUTPUT VOLTAGE (mV)
1500
1000
500
30
60
90
120
150
0
0
2000
V
IN
= 3.6V
HP = BATT
SUPPLY CURRENT vs. SUPPLY VOLTAGE
IN PWM MODE
MAX8506 toc06
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)
5.0
4.5
4.0
3.5
3.0
2.5
1
2
3
4
5
6
0
2.0
5.5
V
OUT
= 1.2V
V
OUT
= 0.4V
200
300
400
500
600
700
800
900
1000
100
SUPPLY CURRENT vs. SUPPLY VOLTAGE
IN NORMAL MODE
MAX8506 toc07
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (
µ
A)
5.0
4.5
4.0
3.5
3.0
2.5
2.0
5.5
V
OUT
= 1.2V
V
OUT
= 3.4V
V
OUT
= 0.4V
SKIP = GND
HEAVY-LOAD SWITCHING WAVEFORM
MAX8506 toc08
1µs/div
V
LX
2V/div
V
OUT
AC-COUPLED
20mV/div
V
OUT
= 1.2V
LOAD = 10Ω