MP38894 – 4.5A, 42V, 420KHZ STEP-DOWN WITH SYNCHRONIZABLE GATE DRIVER
MP38894 Rev.1.0 www.MonolithicPower.com 2
9/28/2009 MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
© 2009 MPS. All Rights Reserved.
PACKAGE REFERENCE
Part Number* Package Temperature
MP38894DN SOIC8E
–40°C to +85°C
*
For Tape & Reel, add suffix –Z (eg. MP38894DN–Z)
For RoHS Compliant Packaging, add suffix –LF
(eg. MP38894DN–LF–Z)
ABSOLUTE MAXIMUM RATINGS
(1)
Supply Voltage V
IN
....................................... 45V
V
SW
......................... –0.3V(-5V for <10ns) to 46V
V
BST
– V
SW
...................................................... 6V
All Pins........................................... –0.3V to +6V
Junction Temperature...............................150°C
Lead Temperature ....................................260°C
Storage Temperature ..............–65°C to +150°C
Recommended Operating Conditions
(2)
Supply Voltage V
IN
........................... 4.5V to 42V
Output Voltage V
OUT
........................ 0.8V to 15V
Operating Temperature .............–40°C to +85°C
Thermal Resistance
(3)
θ
JA
θ
JC
SOIC8E .................................. 50 ...... 10... °C/W
Notes:
1) Exceeding these ratings may damage the device.
2) The device is not guaranteed to function outside of its
operating conditions.
3) Measured on JESD51-7, 4-layer PCB.
ELECTRICAL CHARACTERISTICS
V
IN
= 12V, T
A
= +25°C, unless otherwise noted.
Parameters Symbol Condition Min Typ Max Units
Feedback Voltage V
FB
4.5V ≤ V
IN
≤ 42V
0.796 0.808 0.820 V
Feedback Current I
FB
V
FB
= 0.8V 10 nA
Switch On Resistance
(4)
R
DS(ON)
100 m
Switch Leakage V
EN
= 0V, V
SW
= 0V 0.1 10 A
Current Limit
(4)
I
O-MAX
Duty=40% 6.5 A
Oscillator Frequency f
SW
V
FB
= 0.6V 240 420 600 kHz
Fold-back Frequency V
FB
= 0V 25 115 205 kHz
Maximum Duty Cycle V
FB
= 0.6V 85 90 %
Minimum On Time
(4)
t
ON
100 ns
Under Voltage Lockout Threshold Rising 3.90 4.10 4.30 V
Under Voltage Lockout Threshold Hysteresis 880 mV
EN Input Low Voltage 0.4 V
EN Input High Voltage 2 V
V
EN
= 2V 2
EN Input Current
V
EN
= 0V 0.1
A
Sync Frequency Range (Low) F
SYNCL
300 kHz
Sync Frequency Range (High) F
SYNCH
1.5 MHz
Enable Turnoff Delay T
OFF
5.0 s
Supply Current (Shutdown) V
EN
= 0V 1 10 A
Supply Current (Quiescent) V
EN
= 2V, V
FB
= 1V 0.9 1.1 mA
Thermal Shutdown 150 °C
BG Driver Bias Supply Voltage V
CC
I
CC
= 5mA 4.5 5.0 V
Gate Driver Sink Impedance
(4)
R
SINK
1
Gate Driver Source Impedance
(4)
R
SOURCE
4
Gate Drive Current Sense Trip Threshold V
SW
20 mV
Note:
4) Guaranteed by design.
SW
BST
VCC
BG
IN
EN/SYNC
FB
GND
1
2
3
4
8
7
6
5
TOP VIEW
EXPOSED PAD
ON BACKSIDE
