LTC1553LCSW#TRMPBF Linear Technology, LTC1553LCSW#TRMPBF Datasheet
LTC1553LCSW#TRMPBF
Specifications of LTC1553LCSW#TRMPBF
Available stocks
Related parts for LTC1553LCSW#TRMPBF
LTC1553LCSW#TRMPBF Summary of contents
Page 1
... The LTC1553L free-runs at 300kHz and can be synchronized to a faster external clock if desired. It includes all the inputs and outputs required to implement a power supply conform- ing to the Intel Pentium Converter Specification . , LTC and LT are registered trademarks of Linear Technology Corporation. Pentium is a registered trademark of Intel Corporation 12V + 0 ...
Page 2
LTC1553L ABSOLUTE MAXIMUM (Note 1) Supply Voltage V ........................................................................ ................................................................... 14V CC Input Voltage I (Note 2) ............................................ ........................................................ – 0. MAX All Other Inputs ......................... – 0.3V to ...
Page 3
ELECTRICAL CHARACTERISTICS SYMBOL PARAMETER I I Sink Current IMAX MAX I Soft Start Source Current SS I Maximum Soft Start Sink Current SSIL Under Current Limit I Soft Start Sink Current Under Hard SSHIL Current Limit t Hard Current Limit ...
Page 4
LTC1553L W U TYPICAL PERFORMANCE CHARACTERISTICS Typical 2.8V V Distribution OUT 140 TOTAL SAMPLE SIZE = 1500 120 100 100 2.775 2.785 2.795 2.805 2.815 2.825 OUTPUT VOLTAGE (V) 1553L G01 Line ...
Page 5
W U TYPICAL PERFORMANCE CHARACTERISTICS Oscillator Frequency vs Temperature 350 340 330 320 310 300 290 280 270 260 250 – 100 125 –25 TEMPERATURE ( C) 1553L G10 Maximum G1 Duty Cycle vs Temperature 92 ...
Page 6
LTC1553L PIN FUNCTIONS G2 (Pin 1): Gate Drive for the Lower N-Channel MOSFET, Q2. This output will swing from low when G1 is high or when the output is disabled. To prevent undershoot during ...
Page 7
PIN FUNCTIONS VID0, VID1, VID2, VID3, VID4 (Pins 18, 17, 16, 15, 14): Digital Voltage Select. TTL inputs used to set the regulated output voltage required by the processor (Table 3). There is an internal 20k pull-up ...
Page 8
LTC1553L TEST CIRCUITS 100pF 100pF VID0 TO VID4 100pF R C 8.2k C1 150pF 0.1 F 10k SENSE SGND 8 ...
Page 9
CTIO TABLES Table 1. OT Logic OUTEN (V) < 2 > 2 Table 2. PWRGD and FAULT Logic INPUT OUTEN SENSE < 95 > 95% 1 < 105% ...
Page 10
LTC1553L U U APPLICATIONS INFORMATION OVERVIEW The LTC1553L is a voltage feedback, synchronous switch- ing regulator controller (see Block Diagram) designed for use in high power, low voltage step-down (buck) convert- ers designed to satisfy the requirements of ...
Page 11
U U APPLICATIONS INFORMATION Soft Start and Current Limit The LTC1553L includes a soft start circuit which is used for initial start-up and during current limit operation. The SS pin requires an external capacitor to GND with the value determined ...
Page 12
LTC1553L U U APPLICATIONS INFORMATION Table 4. Recommended Minimum R IMAX MAXIMUM OPERATING LOAD CURRENT (A) SUD50N03-10 12 2.4 14 2.7 16 3.0 18 3.6 20 3.9 OUTEN and Thermistor Input The LTC1553L includes a low power shutdown mode, controlled ...
Page 13
U U APPLICATIONS INFORMATION 1N5817 OPTIONAL FOR V > 1N5243B 13V 0.1 F LTC1553L Figure 7. Doubling Charge Pump If the OUTEN pin is low, G1 and G2 are both held ...
Page 14
LTC1553L U U APPLICATIONS INFORMATION Table 5. Recommended MOSFETs for LTC1553L Applications R DS(ON) PARTS Siliconix SUD50N03-10 TO-252 Siliconix Si4410DY SO-8 Motorola MTD20N03HDL D PAK SGS-Thomson STD20N03L D PAK Motorola MTB75N03HDL 7.5 DD PAK IRF ...
Page 15
U U APPLICATIONS INFORMATION Solving this equation with our typical 5V to 2.8V applica- tion with inductor, we get P-P 300 kHz 2 H Peak inductor current at 11.2A load: 2 ...
Page 16
LTC1553L APPLICATIONS INFORMATION Feedback Loop Compensation The LTC1553L voltage feedback loop is compensated at the COMP pin, attached to the output node of the internal g error amplifier. The feedback loop can generally be m compensated properly ...
Page 17
U U APPLICATIONS INFORMATION Table 6 shows the suggested compensation components for 5V input applications based on the inductor and output capacitor values. The values were calculated using mul- tiple paralleled 330 F AVX TPS series surface mount tantalum capacitors ...
Page 18
LTC1553L U U APPLICATIONS INFORMATION ground plane at a single point, preferably at a fairly quiet point in the circuit such as close to the output capaci- tors. This is not always practical, however, due to physical constraints. Another reasonably ...
Page 19
... FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE 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 represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights. ...
Page 20
... S20 (WIDE) 0396 20V IN 48V, for Standard Threshold FETs IN 40V, for Logic Threshold FETs IN 36V IN 1553lf LT/TP 0198 4K • PRINTED IN USA LINEAR TECHNOLOGY CORPORATION 1998 ...