A4405 Datasheet, PDF (7/27 Pages) Allegro MicroSystems – The A4405 is an automotive power management IC that uses a high frequency constant on-time 5.45 V pre-regulator to supply two internal 5 V linear regulators and a 3.3 V linear DMOS driver.

A4405
Constant On-Time Buck Regulator
With One External and Two Internal Linear Regulators
ELECTRICAL CHARACTERISTICS (continued) Valid at –40°C ≤ T_J ≤ 150°C, 5.5 V ≤ V_IN ≤ 36 V; unless otherwise specified
Characteristic
Symbol
Test Conditions
Min.
Typ.
Max.
Unit
5 V Linear Regulators
V5 Accuracy and Load Regulation
V5P Accuracy and Load Regulation
V5P/V33 Tracking Ratio
V5P/V33 Tracking Accuracy
Linear Regulator and FET Driver
V_V5
V_V5P
V5P_track
Err_V5Ptrack
10 mA < I_V5 < 215 mA, V_VREG ≥ 5.25 V
10 mA < I_V5P < 270 mA, V_VREG ≥ 5.25 V
V_V5P / V_V33
2.69 V < V_V33 < 3.37 V, I_V5P = 75 mA,
5.5 V < V_IN < 27 V
4.9
5.0
5.1
V
4.9
5.0
5.1
V
1.507
1.515
1.523
–
−0.5
–
+0.5
%
V33 Accuracy
G33 Source Current¹
G33 Sink Current¹
G33 Maximum Voltage
G33 Minimum Voltage
G33 Output Impedance²
External FET Gate Capacitance²
Charge Pump (VCP Pin)
Err_V33
I_G33(SRC)
I_G33(SINK)
V_G33(MAX)
V_G33(MIN)
R_OUT
C_ISS
10 mA < I_V33 < 500 mA
V_V33 = 3.0 V, V_G33 = V_G33(MAX) – 1 V
V_V33 = 3.6 V, V_G33 = 6 V
V_V33 = 3.0 V
V_V33 = 3.6 V
3.23
3.30
3.37
V
−175
−250
−400
μA
0.5
3
–
mA
9
–
15
V
–
0.7
1.0
V
–
175
–
Ω
250
–
5200
pF
Output Voltage
Switching Frequency
Logic Enable Input (ENB Pin)
ΔV_VCP
f_SW(CP)
V_VCP − V_IN
4.1
6.6
–
V
–
100
–
kHz
ENB Logic Input Threshold
V_ENB(H)
V_ENB(L)
V_ENB rising
V_ENB falling
ENB Logic Input Current¹
I_ENB(IN) V_ENB = 3.3 V
ENB Pull-Down Resistance
R_ENB
Ignition Enable Input (ENBAT and ENBATS Pins)
–
–
2.0
V
0.8
–
–
V
–
–
100
μA
–
60
–
kΩ
ENBAT and ENBATS Thresholds
V_IGN(H)
V_IGN(L)
ENBAT Input Current¹
I_ENBAT(IN)
ENBAT Input Resistance
R_ENBAT
Ignition Status Output (ENBATS Pin)
V_IGN rising via a 1 kΩ series resistance,
measure V_IGN when I_Q occurs
V_IGN falling via a 1 kΩ series resistance,
measure V_IGN when I_Q(SLEEP) occurs
V_IGN = 5.5 V via a 1 kΩ series resistance
V_IGN = 0.8 V via a 1 kΩ series resistance
–
–
4.0
V
2.2
–
–
V
–
50
100
μA
0.5
–
5
μA
–
650
–
kΩ
ENBATS Output Voltage
ENBATS Leakage Current¹
ENBATS Turn-On Delay
V_ENBATS(L)
I_ENBATS
t_ENBATS
I_ENBATS = 4 mA
V_ENBATS = 3.3 V
Sleep mode to V_ENBATS = 3.3 V
–
–
400
mV
–
–
1
μA
–
11
–
ms
Continued on the next page…
Allegro MicroSystems, Inc.
7
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com