LT3755IMSE-1#PBF Linear Technology, LT3755IMSE-1#PBF Datasheet
LT3755IMSE-1#PBF
Specifications of LT3755IMSE-1#PBF
Related parts for LT3755IMSE-1#PBF
LT3755IMSE-1#PBF Summary of contents
Page 1
... CTRL input provides additional analog dimming capability. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. True Color PWM is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. ...
Page 2
... LT3755EUD-2#TRPBF LT3755IUD-2#PBF LT3755IUD-2#TRPBF LT3755EMSE#PBF LT3755EMSE#TRPBF LT3755IMSE#PBF LT3755IMSE#TRPBF LT3755EMSE-1#PBF LT3755EMSE-1#TRPBF LT3755IMSE-1#PBF LT3755IMSE-1#TRPBF LT3755EMSE-2#PBF LT3755EMSE-2#TRPBF LT3755IMSE-2#PBF LT3755IMSE-2#TRPBF LT3755HMSE-2#PBF LT3755HMSE-2#TRPBF Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. Consult LTC Marketing for information on non-standard lead based finish parts. ...
Page 3
T PARAMETER V Minimum Operating Voltage IN V Shutdown Operating I (Not Switching Voltage REF V Line Regulation REF SENSE Current Limit Threshold SENSE Input ...
Page 4
LT3755/LT3755-1/LT3755-2 elecTrical characTerisTics temperature range, otherwise specifications are at T PARAMETER Linear Regulator INTV Regulation Voltage CC Dropout (V – INTV ) IN CC INTV Undervoltage Lockout CC INTV Current Limit CC INTV Current in Shutdown CC Logic Inputs/Outputs PWM ...
Page 5
Typical perForMance characTerisTics V Threshold vs V (ISP – ISN) CTRL 120 100 –20 0 0.5 1 1.5 V (V) CTRL 37551 G01 FB Regulation Voltage vs Temperature 1.28 1.27 1.26 1.25 1.24 1.23 1.22 ...
Page 6
LT3755/LT3755-1/LT3755-2 Typical perForMance characTerisTics Quiescent Current 2.0 PWM = 0V 1.5 1.0 0 (V) IN 37551 G10 INTV Voltage ...
Page 7
Typical perForMance characTerisTics ISP/ISN Input Bias Current vs CTRL Voltage 0.5 1 CTRL (V) pin FuncTions (MSOP/QFN) PWMOUT (Pin 1/Pin 11): Buffered Version of PWM Signal for Driving LED Load Disconnect NMOS or Level ...
Page 8
LT3755/LT3755-1/LT3755-2 pin FuncTions (MSOP/QFN) CTRL (Pin 6/Pin 16): Current Sense Threshold Adjustment Pin. Regulating threshold V (ISP – ISN) an offset for 0V < V < 1V. For V CTRL CTRL sense threshold is constant at the full-scale value of ...
Page 9
DiagraM SHDN/UVLO A6 FB – SHDN 1.22V + 2.1µA 1.25V SHORT-CIRCUIT DETECT + SCILMB A10 + – 150mV – ISN 5k ISP CTRL BUFFER CTRL + + 1. – 140µA V REF – 170k ...
Page 10
LT3755/LT3755-1/LT3755-2 operaTion The LT3755 is a constant-frequency, current mode control- ler with a low side NMOS gate driver. The GATE pin and PWMOUT pin drivers and other chip loads are powered from INTV , which is an internally regulated supply. ...
Page 11
INTV Regulator Bypassing and Operation CC The INTV pin requires a capacitor for stable operation CC and to store the charge for the large GATE switching cur- rents. Choose a 10V rated low ESR, X7R or X5R ceramic ...
Page 12
LT3755/LT3755-1/LT3755-2 applicaTions inForMaTion When V is higher than 1.2V, the LED current is CTRL regulated to: 100mV I = LED R LED The LED current programming feature can increase total dimming range by a factor of 10. The CTRL pin ...
Page 13
To make PWM dimming more accurate, the switch demand current is stored on the VC node dur- ing the quiescent phase when PWM is low. This feature ...
Page 14
LT3755/LT3755-1/LT3755-2 applicaTions inForMaTion when operating at high ambient temperatures. The ma- jority of the power dissipation in the IC comes from the supply current needed to drive the gate capacitance of the external power MOSFET. This gate drive current can ...
Page 15
Therefore, a 10µF capacitor is an appropriate selection for a 400kHz boost regulator with 12V input, 48V output and 1A load. With the same V voltage ripple of 100mV, the input capaci- IN tor for a buck converter ...
Page 16
LT3755/LT3755-1/LT3755-2 applicaTions inForMaTion Schottky Rectifier Selection The power Schottky diode conducts current during the interval when the switch is turned off. Select a diode rated for the maximum SW voltage. If using the PWM feature for dimming important ...
Page 17
The inductor and output capacitor are chosen based on performance, size and cost. The compensation resistor and capacitor at VC are selected to optimize control loop response and stability. For typical LED applications, a 2.2nF compensation capacitor at ...
Page 18
LT3755/LT3755-1/LT3755-2 applicaTions inForMaTion GND COMPONENT DESIGNATIONS ...
Page 19
Typical applicaTions 40V IN 4.7µF Efficiency vs Load 100 V = 12V 0.0 0.4 0.6 0.2 LOAD (A) LT3755/LT3755-1/LT3755-2 50W White LED Headlamp Driver L1 22µ ...
Page 20
LT3755/LT3755-1/LT3755-2 Typical applicaTions V IN 15V TO 40V C1 1µF INTV CC 100k 0.1µF L1: COILTRONICS DR125-330 M1: VISHAY SILICONIX SI7850DP D1: ON SEMICONDUCTOR MBRS360 M2: ZETEX ZXMN4A06G M3: ZETEX ZXM62P03E6 Q1: ZETEX FMMT558 1000:1 PWM Dimming at 120Hz with ...
Page 21
Typical applicaTions Buck Mode 500mA LED Driver for 20kHz PWM Dimming V IN 22V TO 36V 1M 68.1k 4.7µF 0.1µF L1: TOKO 962BS_3R3M M1: VISHAY SILICONIX SI7850DP M2: VISHAY SILICONIX SI2306DS D1: DIODES, INC SBM540 Minimum PWM Pulse Switching Waveform ...
Page 22
LT3755/LT3755-1/LT3755-2 Typical applicaTions 21W Buck-Boost Mode with 250:1 PWM Dimming and Open LED Protection 36V 499k 549k 93.1k 4.7µF 75.0k Buck-Boost Mode Efficiency vs Input Voltage 100 ...
Page 23
DescripTion 2.845 0.102 (.112 .004) 5.23 (.206) MIN 0.305 0.038 (.0120 .0015) TYP RECOMMENDED SOLDER PAD LAYOUT DETAIL “A” 0.254 (.010) GAUGE PLANE DETAIL “A” 0.18 (.007) NOTE: 1. DIMENSIONS IN MILLIMETER/(INCH) 2. DRAWING NOT TO SCALE 3. DIMENSION ...
Page 24
LT3755/LT3755-1/LT3755-2 package DescripTion 3.50 ± 0.05 1.45 ± 0.05 (4 SIDES) 2.10 ± 0.05 RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS 3.00 ± 0.10 PIN 1 TOP MARK (NOTE 6) NOTE: 1. DRAWING CONFORMS TO JEDEC PACKAGE OUTLINE MO-220 VARIATION (WEED-2) ...
Page 25
... Revised Entire Data Sheet to Include H-Grade Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa- tion that the interconnection of its circuits as described herein will not infringe on existing patent rights. ...
Page 26
... True Color PWM Dimming = 1000:1, OUT(MAX) = 45V, Dimming = 3000:1, OUT(MAX) = 45V, Dimming = 3000:1, OUT(MAX) = 45V, Dimming = 3000:1, OUT(MAX) = 100V, True Color PWM Dimming = 3000:1, OUT(MAX) = Ext FET, True Color PWM Dimming = 3000:1, OUT(MAX) LT 0310 REV D • PRINTED IN USA LINEAR TECHNOLOGY CORPORATION 2008 37551fd ...