A4402_1 ALLEGRO [Allegro MicroSystems], A4402_1 Datasheet - Page 4

• Manufacturer Part Number: A4402_1
• Description: Constant On-Time Buck Converter with Integrated Linear Regulator
• Manufacturer: ALLEGRO [Allegro MicroSystems]

A4402
Continued on the next page…
ELECTRICAL CHARACTERISTICS
Input Voltage Supply 1
Input Voltage Supply 2
Supply Quiescent Current
ENB Logic Input Voltage
ENB Hysteresis
ENB Logic Input Current
Linear Regulator
Output Voltage Range
Feedback Voltage
V
Threshold
V
Hysteresis
Feedback Input Bias Current
Current Limit
Dropout Voltage
Switching Regulator
Output Voltage Range
Feedback Voltage
Feedback Input Bias Current
Switcher On Time
t
t
Changeover Hysteresis
On-time Accuracy
Minimum On-time
Minimum Off-time
Buck Switch On-Resistance
ISEN Voltage
Valley Current Limit Threshold
on
on
O2
O2
Low Voltage Threshold
High Voltage Threshold
Undervoltage Lockout
Undervoltage Lockout
Characteristics
V
V
Symbol
V
R
O2UVHYS
V
ENBHYS
O2UVLO
V
err
t
t
I
V
V
V
V
V
V
I
V
V
I
I
V
onmin
offmin
DS(on)
IN(Q)
DROP
V
ENB
I
I
FB2
FB1
t
ISEN
ENB
HYS
FB2
O2
FB1
lim
IN1
IN2
SW
on
O2
PH
PL
ton
1,2
valid at T
VIN2 = V
ENB = 5 V, I
VIN1 = 13.5 V, ENB = 0 V,
I
V
High input level, V
Low input level, V
1 mA < I
V
I
I
V
V
V
V
V
T
T
R
6 V < V
OUT
OUT
OUT
ENB
O2
IN
IN
IN
IN
IN
J
J
SENSE
= 25°C, I
= 125°C, I
= 19.25 V, R
= 13.5 V, R
= 8 V, R
rising
rising
rising based on FB voltage
= I
= I
= I
J
rising
= 25°C, V
SW
SW
SW
IN
= 0.27 Ω
O2
SW
< 8 V
+ I
+ I
+ I
< 250 mA, 3.3 V < V
LOAD
ton
OUT
LIN
LIN
LIN
LOAD
= 750 kΩ
ton
= 250 mA
= 1 mA to 1.0 A, 8 V < V
= 0 mA
ton
= I
= 1 A
ENB
= 750 kΩ
ENB
= 1 A
IN
Test Conditions
SW
= 750 kΩ
Constant On-Time Buck Converter
= 13.5 V (unless otherwise noted)
+ I
< 0.4 V
= 3 V
with Integrated Linear Regulator
LIN
= 0 mA, V
IN2
< 5 V
IN
= 13.5 V
IN
< 18 V
115 Northeast Cutoff
1.508.853.5000; www.allegromicro.com
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 U.S.A.
1.156
0.896
1.156
15.75
–100
–400
Min.
250
185
–30
130
3.3
2.0
1.8
3.3
8.1
–2
30
80
6
–
–
–
–
–
–
–
–
–
–
–
–
–
1.180
0.944
1.180
–100
–200
Typ.
13.5
2.28
17.5
100
100
670
235
250
400
650
740
1.4
10
50
–
–
–
–
–
–
–
–
9
–
–
–
–
1.204
0.990
1.204
19.25
Max.
2.56
100
400
350
100
285
550
3.3
1.2
9.9
50
70
30
5
–
1
–
2
5
–
–
–
–
–
–
–
–
–
Units
mΩ
mΩ
mA
mV
mV
mA
mV
mV
mA
mA
μA
μA
μA
nA
nA
ns
ns
μs
ns
ns
%
V
V
V
V
V
V
V
V
V
V
V
4