_______________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
High-Side MOSFET Driver for HB LED Drivers
and DC-DC Applications
MAX15054
General Description
The MAX15054 is a high-side, n-channel MOSFET driver
for high-voltage applications capable of switching at high
frequencies. This device is controlled by a CMOS logic-
level signal referenced to ground and features a very
short (12ns, typ) propagation delay from input to output.
The high-voltage operation and high source/sink-current
capability make the MAX15054 ideal for HB LED drivers
and DC-DC converters.
The MAX15054 is well suited to complement other Maxim
LED driver products such as the MAX16814, MAX16838,
MAX16833, MAX16834, and MAX16826. The MAX15054
adds a high-side driver to those products that include only a
low-side driver; it then allows for buck-boost configurations
for multistring drivers similar to the MAX16814, MAX16838,
and MAX16826, and for buck-boost conversion with output
referenced to ground for single-string drivers such as the
MAX16834 and MAX16833.
The MAX15054 is available in the industry-standard 6-pin
SOT23 package and operates over the -40NC to +125NC
automotive temperature range.
Applications
HB LED Drivers for Single and Multiple Strings
LED Backlight Drivers
High-Side Driver for DC-DC Converters
(Buck, Buck-Boost, Half-Bridge, Full-Bridge)
Features
S Input Voltage on High-Side n-Channel MOSFET Up
to 60V
S Up to 13.5V Logic Input Independent of Supply
Voltage
S 2A Peak Source and Sink Current
S 12ns Propagation Delay
S Rise and Fall Times of 6ns while Driving 1000pF
Capacitance
S Low Input Capacitance
S Low-Side and High-Side Undervoltage Protection
S Allows Buck-Boost Topology Referred to Ground
for LED Drivers and DC-DC Converters
S Allows Buck-Boost Topology for Multistring LED
Drivers
S 6-Pin SOT23 Package
19-4747; Rev 0; 9/09
+Denotes a lead(Pb)-free/RoHS-compliant package.
Pin Configuration appears at end of data sheet.
Ordering Information
PART TEMP RANGE PIN-
PACKAGE
TOP
MARK
MAX15054AUT+ -40NC to +125NC6 SOT23 ACOM
Typical Operating Circuits
Q1
D1
D2
L1
CBST
VDD
VIN
GND HI
BST
HDRV
LX
EN
VCC
VDRV
DIM
COMP
DRAIN
OV
OUT1
OUT2
ISET
FLT
CS
RT
SGND PGND
IN GATE NDRV
LEDGND
C1
MAX15054
MAX16838
D3
R8
R9
C5
R5
R7
R6
R4
C4
C4
C3
C2
R3
R2
R1
CFB
Typical Operating Circuits continued at end of data sheet.
High-Side MOSFET Driver for HB LED Drivers
and DC-DC Applications
MAX15054
2 ______________________________________________________________________________________
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
VDD to GND ............................................................. -0.3V to +6V
LX to GND ................................................................ -2V to +65V
HDRV to LX ................................................-0.3V to (VDD + 0.3V)
BST to LX ................................................................. -0.3V to +6V
HI to GND .............................................................. -0.3V to +15V
dV/dt at LX ........................................................................ 50V/ns
Peak Current into HDRV (< 100ns) ...................................... Q2A
Continuous Current into HDRV ..................................... Q100mA
Continuous Power Dissipation (TA = +70NC)
6-Pin SOT23 (derate 8.7mW/NC above +70NC) .........695.7mW
Thermal Resistance (Note 1)
Junction-to-Ambient Thermal Resistance (BJA) .........115NC/W
Junction-to-Case Thermal Resistance (BJC) ................80NC/W
Operating Temperature Range ........................ -40NC to +125NC
Maximum Junction Temperature .....................................+150NC
Storage Temperature Range ............................ -65NC to +150NC
Lead Temperature (soldering, 10s) .................................+300NC
ELECTRICAL CHARACTERISTICS
(VDD = VBST = 5V, VLX = VGND = 0V, TA = TJ = -40°C to +125°C, unless otherwise noted. Typical values are at TA = TJ = +25°C,
unless otherwise noted.) (Note 2)
ABSOLUTE MAXIMUM RATINGS
Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-
layer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial.
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Operating Supply Voltage VDD 4.6 5.5 V
VDD Quiescent Supply Current IDD No switching 40 75 FA
BST Quiescent Supply Current IBST No switching 65 125 FA
BST Operating Supply Current IBSTO fSW = 500kHz, no load 0.3 1.3 mA
VDD Undervoltage Lockout
Threshold VDD_UVLO VDD rising 3.92 4.22 4.56 V
VDD Undervoltage Lockout
Threshold Hysteresis 0.2 V
BST-to-LX Undervoltage
Lockout Threshold
VBST_
UVLO BST rising 3.54 3.82 4.1 V
BST-to-LX Undervoltage
Lockout Threshold Hysteresis 0.2 V
LOGIC INPUT (HI)
HI Logic-High Threshold VIH 3.9 V
HI Logic-Low Threshold VIL 1.8 V
HI Logic-Input Hysteresis 0.9 V
HI Input Current IIN HI = GND -2 +2 FA
HI Input Resistance RIN 300 kI
DRIVER
LX Withstand Voltage VLX_MAX 60 V
BST Withstand Voltage VBST_MAX 65 V
LX Pulldown Current VLX = 2.5V 500 740 1100 FA
Driver Output Resistance
(Sourcing) RON_HP VBST - VLX = 4.5V,
100mA sourcing
TA = +25NC1 1.5 I
TA = +125NC1.25 2
Driver Output Resistance
(Sinking) RON_HN VBST - VLX = 4.5V,
100mA sinking
TA = +25NC0.75 1 I
TA = +125NC1 1.5
High-Side MOSFET Driver for HB LED Drivers
and DC-DC Applications
MAX15054
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(VDD = VBST = 5V, VLX = VGND = 0V, TA = TJ = -40°C to +125°C, unless otherwise noted. Typical values are at TA = TJ = +25°C,
unless otherwise noted.) (Note 2)
Note 2: All devices are 100% production tested at TA = +25NC. Limits over the operating temperature range are guaranteed by
design.
Note 3: Guaranteed by design.
Figure 1. Turn-On/Turn-Off Propagation Delay
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Peak Output Current (Sourcing) IPK_HP VHDRV = 0V 2.5 A
Peak Output Current (Sinking) IPK_HN VHDRV = 5V 2.5 A
SWITCHING CHARACTERISTICS
Rise Time tR
No-load capacitor 1.5
nsCL = 1000pF 6
CL = 5000pF 18
Fall Time tF
No-load capacitor 1.5
nsCL = 1000pF 6
CL = 5000pF 16
Turn-On Propagation Delay tD_ON Figure 1, CL = 1000pF (Note 3) 11 25 ns
Turn-Off Propagation Delay tD_OFF Figure 1, CL = 1000pF (Note 3) 11 25 ns
VHI
VIH
VIL
tD_OFF
tF
tD_ON
10%
90%
tR
VHDRV
High-Side MOSFET Driver for HB LED Drivers
and DC-DC Applications
MAX15054
4 ______________________________________________________________________________________
Typical Operating Characteristics
(VDD = VBST = 5V, VLX = VGND = 0V, TA = +25°C, unless otherwise noted.)
BST OPERATING SUPPLY CURRENT
vs. SWITCHING FREQUENCY
MAX15054 toc06
SWITCHING FREQUENCY (kHz)
IBSTO (µA)
10001001.0 10
250
500
750
1000
1250
1500
1750
2000
0
0.1 10,000
NO LOAD ON HDRV
HI INPUT THRESHOLDS vs. TEMPERATURE
MAX15054 toc07
TEMPERATURE (NC)
INPUT THRESHOLD (V)
11095-25 -10 5 35 50 6520 80
2.25
2.50
2.75
3.00
3.25
3.50
3.75
4.00
2.00
-40 125
RISING
FALLING
POWER-UP AND POWER-DOWN SEQUENCE
MAX15054 toc04
0V
HDRV
1V/div
VDD
1V/div
40µs/div
fSW = 5kHz AT HI
VDD, BST-LX QUIESCENT SUPPLY
CURRENT vs. SUPPLY VOLTAGE
MAX15054 toc05
SUPPLY VOLTAGE (V)
QUIESCENT CURRENT (µA)
5.04.53.5 4.01.0 1.5 2.0 2.5 3.00.5
5
10
15
20
25
30
35
40
45
50
55
60
65
70
0
5.5
TA = +125NC
IBST
IDD
TA = +85NC
TA = +25NC
TA = -40NC
VDD UNDERVOLTAGE LOCKOUT
THRESHOLD vs. TEMPERATURE
MAX15054 toc01
TEMPERATURE (NC)
UVLO THRESHOLD (V)
1109565 80-10 5 20 35 50-25
4.000
4.025
4.050
4.075
4.100
4.125
4.150
4.175
4.200
4.225
VDD RISING
VDD FALLING
4.250
3.975
-40 125
BST-LX UNDERVOLTAGE LOCKOUT
THRESHOLD vs. TEMPERATURE
MAX15054 toc02
TEMPERATURE (°C)
UVLO THRESHOLD (V)
1109565 80-10 5 20 35 50-25
3.625
3.650
3.675
3.700
3.725
3.750
3.775
3.800
3.825
3.850
3.875
3.600
-40 125
BST-LX FALLING
BST-LX RISING
POWER-UP AND POWER-DOWN SEQUENCE
MAX15054 toc03
0V
HDRV
1V/div
VDD
1V/div
400µs/div
fSW = 5kHz AT HI
High-Side MOSFET Driver for HB LED Drivers
and DC-DC Applications
MAX15054
_______________________________________________________________________________________ 5
Typical Operating Characteristics (continued)
(VDD = VBST = 5V, VLX = VGND = 0V, TA = +25°C, unless otherwise noted.)
2MHz OPERATION
MAX15054 toc08
0V
0V
HDRV
2V/div
HI
2V/div
200ns/div
NO LOAD ON HDRV
HDRV OUTPUT HIGH/LOW
vs. TEMPERATURE
MAX15054 toc09
TEMPERATURE (NC)
OUTPUT HIGH/LOW (V)
1109580655035205-10-25
20
40
60
80
100
120
140
0
-40 125
VBST - VHDRV
SOURCING 100mA
VHDRV - VLX
SINKING 100mA
OUTPUT HIGH = VBST - VHDRV
OUTPUT LOW = VHDRV - VLX
4% DUTY CYCLE AT 2MHz
MAX15054 toc10
10ns/div
HI
2V/div
0V
0V
HDRV
2V/div
96% DUTY CYCLE AT 2MHz
MAX15054 toc11
2V/div
2V/div
10ns/div
TURN-ON/TURN-OFF PROPAGATION
DELAY vs. TEMPERATURE
MAX15054 toc12
TEMPERATURE (°C)
PROPAGATION DELAY (ns)
110
9565 80-10 5 20 35 50-25
8.5
9.0
9.5
10.0
10.5
11.0
11.5
12.0
12.5
13.0
8.0
-40 125
tD_ON
tD_OFF
RISE TIME AND FALL TIME
MAX15054 toc13
0V
0V
2V/div
2V/div
20ns/div
HI
HDRV
HDRV
4.7nF CAPACITOR
CONNECTED FROM
HDRV TO GND,
LX = GND
HI
TURN-ON AND TURN-OFF
PROPAGATION DELAY
MAX15054 toc14
0V
1V/div
40ns/div
1nF CAPACITOR CONNECTED
FROM HDRV TO GND,
LX = GND
HI
HDRV
High-Side MOSFET Driver for HB LED Drivers
and DC-DC Applications
MAX15054
6 ______________________________________________________________________________________
Pin Description
Functional Diagram
Detailed Description
The MAX15054 n-channel MOSFET driver controls an
external high-side MOSFET in high-voltage, high-current
applications. This driver operates with a supply voltage of
4.6V to 5.5V, and consumes only 300FA of supply current
during typical switching operations (fSW = 500kHz) and
no-load conditions. The MAX15054 provides 2.5A (typ)
sink/source peak current and is capable of operating with
large capacitive loads and with switching frequencies
up to 2MHz. The device is used to drive the high-side
MOSFET without requiring an isolation device such as an
optocoupler or a drive transformer.
The high-side driver is controlled by a CMOS logic
referenced to ground and is powered by a bootstrap
circuit formed by an external diode and capacitor.
Undervoltage lockout (UVLO) protection is provided for
both the high- and low-side driver supplies (BST and
VDD) and includes a UVLO hysteresis of 0.2V (typ).
The MAX15054’s fast switching times and very short
propagation delays (11ns, typ) are ideal for high-
frequency applications. Internal logic circuitry prevents
shoot-through during output state changes and minimizes
package power dissipation.
LOW-SIDE
UVLO
HDRV
LX
VDD
BST
D1
EXTERNAL
HI
GND
LEVEL
SHIFT UP
HIGH-SIDE
UVLO
LEVEL SHIFT
DOWN
MAX15054
PIN NAME FUNCTION
1 HI 5V CMOS Logic Input. HI is referenced to GND and is capable of withstanding voltages up to 13.5V for
any VDD voltage.
2 GND Ground
3 VDD Input Supply Voltage. Valid supply voltage ranges from 4.6V to 5.5V. Bypass VDD to GND with a 0.1FF
ceramic capacitor as close as possible to the device.
4 BST
Boost Flying Capacitor Connection. Connect a minimum of a 0.1FF ceramic capacitor between BST
and LX for the high-side MOSFET driver supply. Connect a bootstrap Schottky diode between VDD
and BST.
5 HDRV High-Side Gate-Driver Output. Driver output to drive the high-side external MOSFET gate.
6 LX Source Connection for High-Side MOSFET. LX also serves as a return terminal for the high-side driver.
High-Side MOSFET Driver for HB LED Drivers
and DC-DC Applications
MAX15054
_______________________________________________________________________________________ 7
Undervoltage Lockout
The MAX15054 drives an external high-side MOSFET.
Both the high- and low-side supplies feature separate
UVLO protection that monitors each driver’s input supply
voltage (BST-LX and VDD). The low-side supply UVLO
threshold (VDD_UVLO) is referenced to GND and pulls
the driver output low when VDD falls below 4V (typ)
irrespective of the high-side UVLO condition.
The high-side driver UVLO threshold (VBST_UVLO) is
referenced to LX, and pulls HDRV low when VBST falls
below 3.6V (typ) with respect to LX. After the MAX15054 is
first energized (VDD > VDD_UVLO), the bootstrap capacitor
(CBST) between BST and LX is not charged, and HDRV
does not switch since the BST-to-LX voltage is below
VBST_UVLO. An internal charging circuit charges the
BST-LX supply through an external Schottky diode and
within a short time CBST charges through VDD and causes
VBST to exceed VBST_UVLO. HDRV then starts switching
and follows HI. The hysteresis is 0.2V (typ) for both UVLO
thresholds.
Output Driver
The MAX15054 driver contains low on-resistance
p-channel and n-channel devices in a totem pole
configuration for the driver output stage. This allows for
rapid turn-on and turn-off of high gate-charge (Qg)
external switching MOSFETs. The driver exhibits low
drain-to-source resistance (RDS(ON)) that decreases for
lower operating temperatures. Lower RDS(ON) means
higher source and sink currents from the device as
the external MOSFET gate capacitance charges and
discharges at a quicker rate, resulting in faster switching
speeds. The peak source and sink current provided by
the driver is 2.5A (typ).
Propagation delay from the logic input (HI) to the driver
output is 12ns (typ) (Figure 1). The internal driver also
contains break-before-make logic to eliminate shoot-
through conditions that cause unnecessarily high
operating supply currents, efficiency reduction, and
voltage spikes at VDD.
Voltage from HDRV to LX is approximately equal to VDD
minus the diode drop of the bootstrap diode when in a
high state, and zero when in a low state.
Bootstrap Diode
Connect an external Schottky diode between VDD and
BST, in conjunction with an external bootstrap capacitor
(CBST), to provide the voltage required to turn on the
MOSFET (see the Typical Operating Circuits). The diode
charges the bootstrap capacitor from VDD when the
high-side switch is off, and isolates VDD when HDRV is
pulled high when the driver turns on.
Bootstrap Capacitor
The bootstrap capacitor (CBST) between BST and LX is
used to ensure adequate charge is available to switch
the high-side MOSFET. This capacitor is charged from
VDD by an external bootstrap diode when the MOSFET
is off. The bootstrap capacitor value should be selected
carefully to avoid oscillations during turn-on and turn-
off at the HDRV output. Choose a capacitor value at
least 20 times greater than the total gate capacitance
of the MOSFET being switched. Use a low-ESR ceramic
capacitor (typically a minimum 0.1FF is needed). The
high-side MOSFET’s continuous on-time is limited due
to the charge loss from the high-side driver’s quiescent
current. The maximum on-time is dependent on the size
of CBST, IBST (125FA, max), and VBST_UVLO.
Driver Logic Input (HI)
The MAX15054 features a 5V CMOS logic input. The
required logic-input levels are independent of VDD and
are capable of withstanding up to 13.5V. For example,
the MAX15054 can be powered by a 5V supply while the
logic inputs are provided from 12V logic. Additionally, HI
is protected against voltage spikes up to 15V, regardless
of the VDD voltage. The logic input has 900mV hysteresis
to avoid double pulsing during signal transition. The logic
input is a high-impedance input (300kI, typ) and should
not be left unconnected to ensure the input logic state is
at a known level. With the logic input unconnected, HDRV
pulls low as VDD rises above the UVLO threshold. The
PWM output from the controller must assume a proper
state while powering up the device.
High-Side MOSFET Driver for HB LED Drivers
and DC-DC Applications
MAX15054
8 ______________________________________________________________________________________
Typical Operating Circuits (continued)
MAX16814
Q1
Q2
VCC
VIN
D1
D2
D3
L
CBST
VDD
IN
EN
VCC
VDRV
FLAG
DIM
RSDT
COMP
SGND PGND
LEDGND
R9
R5
C5
R3
R2
R1
C3
VCC
C2
C4
R6
CC
RC
R8
R7
ISET
OUT4
OUT1
OVP
NDRV CS
RT
GND
HI
BST
HDRV
LX
C1
C6
C7
R11
R12
R10
R9
COUT
MAX15054
High-Side MOSFET Driver for HB LED Drivers
and DC-DC Applications
MAX15054
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.
Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 9
© 2009 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.
Package Information
For the latest package outline information and land patterns, go
to www.maxim-ic.com/packages.
PACKAGE TYPE PACKAGE CODE DOCUMENT NO.
6 SOT23 U6+1 21-0058
___Chip Information
PROCESS: BiCMOS
Pin Configuration
GND
BSTVDD
1 6 LX
5 HDRV
HI +
MAX15054
SOT23
TOP VIEW
2
3 4
