MAX887 Maxim, MAX887 Datasheet - Page 3

• Manufacturer Part Number: MAX887
• Description: 100% Duty Cycle / Low-Noise / Step-Down / PWM DC-DC Converter
• Manufacturer: Maxim

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