MAX1644 Maxim, MAX1644 Datasheet - Page 4

• Manufacturer Part Number: MAX1644
• Description: Advanced Chemistry-Independent / Level 2 Battery Charger with Input Current Limiting
• Manufacturer: Maxim

2A, Low-Voltage, Step-Down Regulator with
Synchronous Rectification and Internal Switches
(Circuit of Figure 1, T
4
350
300
250
200
150
100
100
500
450
400
350
300
250
200
150
100
50
10
90
80
70
60
50
40
30
20
50
0
_______________________________________________________________________________________
0
0
0.001
0
SUPPLY CURRENT vs. SUPPLY VOLTAGE
0
I
OUT
EFFICIENCY vs. OUTPUT CURRENT
UNDERVOLTAGE
LOCKOUT
= 0
V
V
R
L = 6.0μH,
1
SWITCHING FREQUENCY
IN
OUT
TOFF
0.5
0.01
vs. OUTPUT CURRENT
= 5V,
= 3.3V,
OUTPUT CURRENT (A)
= 120kΩ
OUTPUT CURRENT (A)
SUPPLY VOLTAGE
V
V
R
2
V
L = 6.0μH, R
L = 6.0μH,
IN
OUT
TOFF
IN
= 5V,
= 5V, V
= 1.5V,
A
= 270kΩ
SHDN = V
1.0
0.1
3
= +25°C, unless otherwise noted.)
SHDN = GND
OUT
TOFF
= 3.3V,
IN
4
V
V
R
L = 4.7μH,
= 120kΩ
IN
OUT
TOFF
= V
1.5
1
= 3.3V,
CC
= 1.5V,
= 200kΩ
5
MAX1644-07
2.0
10
6
0.10
0.09
0.08
0.07
0.06
0.05
0.04
0.03
0.02
0.01
0
V
5V/div
1A/div
2V/div
1V/div
SHDN
V
V
OUT
100
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
I
SS
10
IN
90
80
70
60
50
40
30
20
0
0
0
0
0
0
0.001
0
V
EFFICIENCY vs. OUTPUT CURRENT
V
L = 4.7μH, R
IN
IN
100
= 5.0V, V
= 3.3V, V
SHUTDOWN TRANSIENTS
0.01
OFF-TIME vs. R
OUTPUT CURRENT (A)
200
OUT
STARTUP AND
OUT
TOFF
R
= 3.3V, I
= 1.5V,
V
TOFF
= 200kΩ
L = 6.0μH, R
2ms/div
IN
Typical Operating Characteristics
300
0.1
= 5V, V
(kΩ)
OUT
400
OUT
= 2A
TOFF
TOFF
= 1.5V,
1
= 270kΩ
500
600
10
-0.9
-1.0
-0.1
-0.2
-0.3
-0.4
-0.5
-0.6
-0.7
-0.8
0.0001
0
DC LOAD-REGULATION ERROR
A: V
B: V
C: V
D: V
E: V
0.001
R
R
R
R
R
IN
TOFF
IN
TOFF
TOFF
TOFF
IN
TOFF
IN
IN
vs. OUTPUT CURRENT
D
= 5V, V
= 3.3V, V
= 3.3V, V
= 5V, V
= 5V, V
OUTPUT CURRENT (A)
= 200kΩ, FBSEL = GND
= 200kΩ, FBSEL = REF
= 120kΩ, FBSEL = OPEN
= 270kΩ, FBSEL = GND
= 270kΩ, FBSEL = REF
0.01
E
OUT
OUT
OUT
OUT
OUT
= 1.5V, L = 6.0μH,
= 3.3V, L = 6.0μH,
= 1.5V, L = 6.0μH,
= 1.5V, L = 4.7μH,
= 1.5V, L = 4.7μH,
C
0.1
1
A
B
10