MP4689
100V Input, 1A High Power LED Driver
The Future of Analog IC Technology
DESCRIPTION
The MP4689 is a high voltage input step-down switching regulator to deliver a constant current of up to 1A to high power LEDs. It integrates a high-side high voltage power MOSFET with a current limit of 2.5A (typical value). The wide 4.5V to 100V input range accommodates a variety of step-down applications, making it ideal for automotive, industrial and general lighting applications. Hysteresis current mode control is applied for very fast response, which makes the 20kHz dimming frequency possible. MPS’s proprietary feedback control scheme minimizes the number of external components while delivering a LED current with typical ±3% accuracy.
The switching frequency is up to 1MHz, thus allowing for small component size. The thermal shut down, short circuit protection, and optional output voltage limitation provide reliable, fault tolerant operations. A 170µA quiescent current allows its use in battery-powered applications.  The MP4689 is available in SOIC8 with exposed pad packages. FEATURES
• Wide 4.5V to 100V Operating Input Range • No Output Capacitor Required • ±3% LED Current Accuracy
• Hysteretic Control: No Compensation • Up to 1MHz Switching Frequency • Up to 20kHz Dimming Frequency
• Dedicated PWM Dimming Control Input •
Short circuit protection with integrated high side MOSFET
• Optional Output Voltage Limitation • Thermal shut down
• 200mV reference voltage for high efficiency • Up to 95% Efficiency
• 170µA Quiescent Current
• Available in SOIC8 with Exposed Pad
Packages
APPLICATIONS
• High Power LED Driver
• Automotive, Industry and General Lighting  • Constant Current Source
For MPS green status, please visit MPS website under Quality Assurance.“MPS” and “The Future of Analog IC Technology” are Registered Trademarks of Monolithic Power Systems, Inc.
TYPICAL APPLICATION
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ORDERING INFORMATION
Part Number*Package Top Marking Free Air Temperature (T A) MP4689DN SOIC8E MP4689 -40°C to +85°C
* For Tape & Reel, add suffix –Z (e.g. MP4689DN–Z);
For RoHS compliant packaging, add suffix –LF (e.g. MP4689DN–LF–Z)
PACKAGE REFERENCE
ABSOLUTE MAXIMUM RATINGS(1) Supply Voltage (V IN) .................... -0.3V to +100V Switch Voltag
e (V SW) ............. -0.5V to V IN + 0.5V  BST to SW ...................................... -0.3V to +6V All Other Pins .................................. -0.3V to +6V Junction Temperature ............................... 150°C Continuous Power Dissipation  (T A = +25°C) (2) .............................................................
2.5W Lead Temperature .................................... 260°C Storage Temperature ............... -65°C to +150°C Recommended Operating Conditions (3) Supply Voltage 4.5V to 95V EN and DIM Voltages ........................... 0V to 5V Maximum Junction Temp. (T J) ............... +125°C Thermal Resistance (4)θJA θJC
SOIC8E (Exposed Pad) .......... 50 ...... 10 ... °C/W Notes:
1) Exceeding these ratings may damage the device.
2) The maximum allowable power dissipation is a function of the
maximum junction temperature T J(MAX), the junction-to-ambient thermal resistance θJA, and the ambient temperature T A. The maximum allowable continuous power dissipation at any ambient temperature is calculated by P D(MAX)=(T J(MAX)-T A)/θJA. Exceeding the maximum allowable power dissipation will cause excessive die temperature, and the regulator will go into thermal shutdown. Internal thermal shutdown circuitry protects the device from permanent damage.
3) The device is not guaranteed to function outside of its
operating conditions.
4) Measured on JESD51-7 4-layer board.
ELECTRICAL CHARACTERISTICS
V IN = 60V, T A= +25°C, unless otherwise noted.
Specifications over temperature are guaranteed by design and characterization.
Parameter Symbol
Condition
Min
Typ
Max
Units
VIN UVLO Threshold    3.6    4.0    4.35 V
VIN UVLO Hysteresis 0.4 V
Shutdown Supply Current V EN = 0V    2    5 µA
Quiescent Supply Current No load, V FB = 250mV 170 240 µA
Upper Switch On Resistance (5)R DS(ON)V BST – V SW = 5V 500 mΩ
Upper Switch Leakage Current I SWLK V EN = 0V, V SW = 0V 0.01    1 µA
Current Limit I PK V FB = 0.15V    1.7    2.5    A
EN Up Threshold V ENH    1.4
1.55
1.7
V EN Threshold Hysteresis V ENHY320
mV EN Input Current I ENI V EN =5V 0.01    1 µA
EN Sinking Current I ENS V EN
bootstrap 5=2V    2 3 µA
DIM Up Threshold V DIMH 0.8
1.15
1.5
V DIM Threshold Hysteresis V DIMHY300
mV DIM Input Current I DIM V DIM =5V or 0V -1    1 µA
DIM On Propagation Delay T DIMDH V FB=0V, V DIM Rising edge to
V SW Rising Edge
50  ns
DIM Off Propagation Delay T DIMDL V FB=0V, V DIM Falling edge to
V SW Falling Edge
50  ns
Feedback Voltage Threshold High (5)V FBH 4.5V < V IN < 95V, V FB rising
from 0V until V SW < 30V
209 215 221 mV
Feedback Voltage Threshold Low (5)V FBL 4.5V < V IN < 95V, V FB falling
from 0.25V until V SW > 30V
179 185 191 mV
FB Pin Input Current I FB V FB=5V or 0V -300 300 nA
FB Propagation Delay to Output High T FBDH
Falling edge of V FB from
0.25V to 0V to V SW rising
edge
100 ns
FB Propagation Delay to Output High T FBDL
Rising edge of V FB from 0V
to
0.25V to V SW falling edge
100 ns
Thermal Shutdown Hysteresis = 20°C  150 °C Note:
5) Guaranteed by design.
PIN FUNCTIONS
SOIC8E
Pin #
Name Description
1 FB Feedback. This is the input to hysteretic comparators. An external current sensing resistor is
connected in series with the LEDs to GND. The feedback voltage is connected to this pin
and is regulated at +200mV with 15% current ripple.
2 N/C Not connected
3 VIN Input Supply. This supplies power to all the internal control circuitry, both BS regulators and
the high-side switch. A decoupling capacitor to ground must be placed close to this pin to
minimize switching spikes.
4 BST
Bootstrap. This is the positive power supply for the internal floating high-side MOSFET
driver. Connect a bypass capacitor between this pin and SW pin.
5 SW
Switch Node. This is the output from the high-side switch. A low V F  Schottky rectifier to
ground is required. The rectifier must be close to the SW pins to reduce switching spikes. 6 DIM PWM Dimming Input. Pulling this pin below the specified threshold for dimming off. Pulling it
up above the specified threshold for dimming on. If there is no need for dimming function,
connect DIM and EN pins together.
7 EN
Enable Input. Pulling this pin below the specified threshold shuts the chip down. Pulling it up
above the specified threshold or leaving it floating enables the chip.
8 GND, Exposed pad Ground. It should be connected as close as possible to the output capacitor avoiding the
high current switch paths. Connect exposed pad to GND plane for optimal thermal
performance.
BLOCK DIAGRAM
BST
SW
FB
GND
Figure 1—Function Block Diagram