MAX1845 Maxim, MAX1845 Datasheet - Page 6

• Manufacturer Part Number: MAX1845
• Description: Dual / High-Efficiency / Step-Down Controller with Accurate Current Limit
• Manufacturer: Maxim

Dual, High-Efficiency, Step-Down
Controller with Accurate Current Limit
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 1, V
6
Note 2: When the inductor is in continuous conduction, the output voltage will have a DC regulation level higher than the error compara-
Note 3: On-time and off-time specifications are measured from 50% point to 50% point at DH_ with LX_ = GND, BST_ = 5V, and a
Note 4: Production testing limitations due to package handling require relaxed maximum on-resistance specifications for the QFN
Note 5: Specifications to -40°C are guaranteed by design, not production tested.
(Circuit of Figure 1, components from Table 1, V
__________________________________________Typical Operating Characteristics
Current-Limit Threshold
(Adjustable)
V
Threshold
Logic Input High Voltage
Logic Input Low Voltage
Logic Input Current
CC
_______________________________________________________________________________________
Undervoltage Lockout
tor threshold by 50% of the output voltage ripple. In discontinuous conduction (SKIP = AGND, light load), the output voltage will
have a DC regulation higher than the error-comparator threshold by approximately 1.5% due to slope compensation.
250pF capacitor connected from DH_ to LX_. Actual in-circuit times may differ due to MOSFET switching speeds.
package. The MAX1845EEI and MAX1845ETX contain the same die, and the QFN package imposes no additional resis-
tance in-circuit.
PARAMETER
DD
400
350
300
250
200
150
100
50
0
0.01
= V
CC
FREQUENCY vs. LOAD CURRENT
OUT1, SKIP = V
OUT2, SKIP = V
OUT1, SKIP = GND
= 5V, SKIP = AGND, V+ = 15V, T
0.1
LOAD CURRENT (A)
SYMBOL
CC
CC
V
V
OUT2, SKIP = GND
IH
IL
1
IN
AGND - V
AGND - V
Rising edge, hysteresis = 20mV, PWMs
disabled below this level
ON_, SKIP
UVP
ON_, SKIP
UVP
TON (AGND or V
ON_, SKIP, UVP
= 15V, SKIP = GND, TON = unconnected, T
10
CS
CS
_, ILIM_ = 0.5V
_, ILIM_ = 1V
A
CONDITIONS
CC
= -40°C to +85°C, unless otherwise noted.) (Note 5)
)
400
350
300
250
200
150
100
50
0
4
FREQUENCY vs. INPUT VOLTAGE
(TON = FLOAT, SKIP = V
8
OUT1
OUT2
INPUT VOLTAGE (V)
12
A
= +25°C, unless otherwise noted.)
V
MIN
4.05
16
2.4
0.4
35
80
CC
-3
-1
-
I
I
OUT1
OUT2
CC
20
= 8A
= 4A
)
TYP
21
MAX
0.05
120
4.4
0.8
65
3
1
UNITS
mV
µA
V
V
V