Typical operating characteristics, Electrical characteristics – Rainbow Electronics MAX887 User Manual
Page 3
MAX887
100% Duty Cycle, Low-Noise,
Step-Down, PWM DC-DC Converter
_______________________________________________________________________________________
3
Note 2:
Specifications from 0°C to -40°C are guaranteed by design and not production tested.
I
OUT
= 0mA, SYNC = GND
V+ rising
I
OUT
= 0mA, SYNC = 3.0V
V+ falling
SYNC = 3.0V
FB = 1.30V
SYNC = 3.0V, PWM duty cycle = 50%
SHDN = GND
Circuit of Figure 2
CONDITIONS
V
3.1
3.5
V
+, START
Startup Voltage
V
3.0
3.3
V
+, UVLO
Undervoltage Lockout
A
0.75
1.00
1.50
I
LIM+
High-Side Current Limit
kHz
250
300
350
f
OSC
PWM Switching Frequency
mA
0.2
0.6
I
V+, PFM
Quiescent Supply Current
(PFM Mode)
mA
2.7
4.0
I
V+, PWM
V
3.5
11.0
V+
Supply Range
Quiescent Supply Current
(PWM Mode)
µA
±0.10
I
FB
FB Input Current
V
1.222
1.250
1.278
V
FB
PWM FB Feedback Threshold
µA
2.5
5
I
V+, SHDN
Shutdown Supply Current
V
1.25
10.50
V
OUT, RANGE
Output Voltage Range
UNITS
MIN
TYP
MAX
SYMBOL
PARAMETER
ELECTRICAL CHARACTERISTICS
(V+ = +7V, PGND = GND = 0V,
SHDN = V+,
(T
A
= -40°C to +85°C)
, unless otherwise noted.) (Note 2)
__________________________________________Typical Operating Characteristics
(Circuit of Figure 2, T
A
= +25°C, unless otherwise noted.)
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0
200
400
600
800
1000
LOAD CURRENT (mA)
DROPOUT VOLTAGE
vs. LOAD CURRENT
MAX887-01
DROPOUT VOLTAGE (V)
3.3V SETTING
V
OUT
= 3.135V
5V SETTING
V
OUT
= 4.75V
0
10
20
30
40
50
60
70
80
90
100
0.0001
0.001
0.01
0.1
0.6
EFFICIENCY (%)
OUTPUT CURRENT (A)
EFFICIENCY vs. OUTPUT CURRENT
MAX887-02
PWM MODE
(SYNC = VL)
V
OUT
= 3.3V
V
IN
= 4V
V
IN
= 5V
V
IN
= 7V
V
IN
= 11V
V
IN
= 9V
0
10
20
30
40
50
60
70
80
90
100
0.0001
0.001
0.01
0.1
0.6
EFFICIENCY (%)
OUTPUT CURRENT (A)
EFFICIENCY vs. OUTPUT CURRENT
MAX887-03
PWM MODE
(SYNC = VL)
V
OUT
= 5V
V
IN
= 9V
V
IN
= 5.5V
V
IN
= 11V
V
IN
= 7V