Datasheet
100
50
0.001 0.01 0.1 1 10
EFFICIENCY vs. OUTPUT CURRENT
(V
IN
= 5.0V, L = 1.5µH)
60
MAX1830 toc01
OUTPUT CURRENT (A)
EFFICIENCY (%)
70
80
90
85
75
65
55
95
V
OUT
= 1.8V
R
TOFF
= 75kΩ
V
OUT
= 1.5V
R
TOFF
= 82kΩ
V
OUT
= 3.3V
R
TOFF
= 39kΩ
100
50
0.001 0.01 0.1 1 10
EFFICIENCY vs. OUTPUT CURRENT
(V
IN
= 3.3V, L = 1.5µH)
60
MAX1830 toc02
OUTPUT CURRENT (A)
EFFICIENCY (%)
70
80
90
85
75
65
55
95
V
OUT
= 1.5V
R
TOFF
= 62kΩ
V
OUT
= 1.8V
R
TOFF
= 51kΩ
V
OUT
= 2.5V
R
TOFF
= 39kΩ
100
50
0.001 0.01 0.1 1 10
EFFICIENCY vs. OUTPUT CURRENT
(f
PWM
= 300kHz)
60
MAX1830 toc03
OUTPUT CURRENT (A)
EFFICIENCY (%)
70
80
90
85
75
65
55
95
V
OUT
= 1.8V
V
IN
= 3.3V
R
TOFF
= 160kΩ
L = 2.5µH
V
OUT
= 1.8V
V
IN
= 5.0V
R
TOFF
= 220kΩ
L = 5.2µH
MAX1830/MAX1831
3A, 1MHz, Low-Voltage, Step-Down Regulators with
Synchronous Rectification and Internal Switches
4 _______________________________________________________________________________________
Typical Operating Characteristics
(Circuit of Figure 1, T
A
= +25°C, unless otherwise noted.)
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= V
CC
= +3.3V, FBSEL = GND, T
A
= -40°C to +85°C, unless otherwise noted.) (Note 5)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Adjustable Output Voltage Range
V
CC
= V
IN
= +3V to +5.5V, I
LOAD
= 0, FBSEL
= GND
V
REF
V
IN
V
Reference Voltage V
REF
1.078 1.122 V
Current-Limit Threshold I
LIMIT
3.9 5.4 A
Idle Mode Current Threshold I
IM
0.14 1.0 A
V
IN
= 4.5V 90
PMOS Switch On-Resistance R
ON
,
P
I
LX
= 0.5A
V
IN
= +3V 110
V
IN
= 4.5V 95
NMOS Switch On-Resistance R
ON
,
N
I
LX
= 0.5A
V
IN
= +3V 100
mΩ
No-Load Supply Current I
IN
+ I
CC
V
FB
= 1.2V 750 µA
FB Input Bias Current I
FB
V
FB
= 1.2V 0 360 nA
Off-Time t
OFF
R
TOFF
= 110kΩ 0.8 1.2 µs
Note 2: Not production tested.
Note 3: Soft-start time is measured with respect to the number of cycles on LX.
Note 4: This is a metal migration limit. Maximum output current may be limited by thermal capability to a lower value than this.
Note 5: Specifications from 0°C to -40°C are guaranteed by design, not production tested.