LM2645

Features: GENERAL`4.5V to 30V input range`Power good function`Input under-voltage lockout`10 A Shutdown/Recycle for entire chip`Thermal shutdown`TSSOP packageSWITCHING SECTION`Two synchronous buck regulators for fixed 5V/3.3V or adjustable outputs`Outputs adjustable from 1.3V to 5.5V`0.04% (typica...

product image

LM2645 Picture
SeekIC No. : 004394947 Detail

LM2645: Features: GENERAL`4.5V to 30V input range`Power good function`Input under-voltage lockout`10 A Shutdown/Recycle for entire chip`Thermal shutdown`TSSOP packageSWITCHING SECTION`Two synchronous buck r...

floor Price/Ceiling Price

Part Number:
LM2645
Supply Ability:
5000

Price Break

  • Qty
  • 1~5000
  • Unit Price
  • Negotiable
  • Processing time
  • 15 Days
Total Cost: $ 0.00

SeekIC Buyer Protection PLUS - newly updated for 2013!

  • Escrow Protection.
  • Guaranteed refunds.
  • Secure payments.
  • Learn more >>

Month Sales

268 Transactions

Rating

evaluate  (4.8 stars)

Upload time: 2024/11/21

Payment Methods

All payment methods are secure and covered by SeekIC Buyer Protection PLUS.

Notice: When you place an order, your payment is made to SeekIC and not to your seller. SeekIC only pays the seller after confirming you have received your order. We will also never share your payment details with your seller.
Product Details

Description



Features:

GENERAL
`4.5V to 30V input range
`Power good function
`Input under-voltage lockout
`10 A Shutdown/Recycle for entire chip
`Thermal shutdown
`TSSOP package
SWITCHING SECTION
`Two synchronous buck regulators for fixed 5V/3.3V or adjustable outputs
`Outputs adjustable from 1.3V to 5.5V
`0.04% (typical) line and load regulation error
`Selectable switching frequency 200/300 kHz
`Two channels operating 180° out of phase
`Separate on/off for each channel
`Separate Power Good signals
`Current mode control with or without sense resistor
`Adjustable cycle-by-cycle current limit
`Skip-mode operation available
`Negative current limit
`Separate soft start for each channel
`Output UVP and OVP
`Programmable output UVP delay
`Self discharge of output capacitors when turned off
LINEAR SECTION
`Adjustable (3.3V to 15V) linear regulator with external PNP pass transistor
`±2% initial tolerance of set voltage
`Output UVP for adjustable linear regulator
`Fixed 3.3V/50mA output rail
`Fixed 5V reference rail



Application

·Notebook and sub-notebook computers
·Embedded computer systems
·Battery-powered instruments
·High end gaming systems
·Set-top boxes
·WebPAD



Pinout

  Connection Diagram


Specifications

If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Voltages from the indicated pins to SGND/PGND:
VIN, ILIM1, ILIM2, KS1, KS2,
LDODRV ....................................................−0.3V to 31V
SW1, SW2, RSNS1, RSNS2 ............−0.3 to (VIN + 0.3)V
VO1, VO2, FB1_FIX, FB2_FIX,
VDD1, VDD2, EXT........................................ −0.3V to 6V
SD, ON1, SS1, ON2, SS2, LDOFB,
FSEL, UV_DELAY, PGOOD1, OUT3,
PGOOD2, COMP1, COMP2,
FPWM/2NDFB
..................................................−0.3V to (VLIN5 +0.3)V
CBOOT1 to SW1, CBOOT2 to SW2 ..............−0.3V to 7V
LDRV1, LDRV2............................... −0.3V to (VDD+0.3)V
HDRV1 to SW1, HDRV2 to SW2............................. −0.3V
HDRV1 to CBOOT1, HDRV2 to
CBOOT2................................................................ +0.3V
Power Dissipation (TA = 25°C,
(Note 2) ...............................................................1.56W
Junction Temperature (TJ)
(Note 2) ...........................................................+150°C
Ambient Storage Temperature
Range .............................................−65°C to +150°C
Soldering Dwell Time, Temperature
(Note 3)
Wave4 sec, ........................................................260°C
Infrared10sec, ...................................................240°C
Vapor Phase75sec, ............................................219°C
ESD Rating (Note 4)................................................. 2kV



Description

The LM2645 is a feature-rich IC that combines two current mode synchronous buck regulator controllers, an adjustable linear regulator controller and a fixed 3.3V standby outputrail.

The two switching regulator controllers operate 180° out of phase. This feature reduces the input ripple RMS current, thereby significantly reducing the required input capacitance. The two switching regulator outputs can also be paralleled to operate as a dual-phase regulator.

The use of synchronous rectification and pulse-skip operation at light load achieves high efficiency over a wide load range. Fixed-frequency operation can be obtained by disabling the pulse-skip mode. The switching frequency of the LM2645 is user selectable between 200 kHz or 300 kHz.

The first switching controller (Channel 1) features a fixed 5V output, and the second switching controller controller (Channel 2) features a fixed 3.3V output. Both channels can also be independently adjusted from 1.3 to 5.5V. The adjustable linear regulator can be adjusted from 3.3V to 15V. An internal 5V rail is also available externally for driving bootstrap circuitry. This rail also serves as the input for an internal LDO that provides the fixed 3.3V/50mA output rail.

Current-mode feedback control assures excellent line and load regulation and a wide loop bandwidth for excellent response to fast load transients. Current is sensed across either the Vds of the top FET or across an external sense resistor connected in series with the drain of the top FET. Current limit is independently adjustable for each channel. The analog soft-start for the switching controllers uses an innovative new approach. It is independent of the input voltage which makes the soft-start behavior more predictable and controllable.

Independant PGOOD signals monitor each of the switching regulator outputs. The switching outputs have under-voltage and over-voltage latch protection, while the output of the external linear regulator has undervoltage latch protection. The undervoltage latch can be disabled or adjustably delayed.




Customers Who Bought This Item Also Bought

Margin,quality,low-cost products with low minimum orders. Secure your online payments with SeekIC Buyer Protection.
Isolators
Undefined Category
Boxes, Enclosures, Racks
Static Control, ESD, Clean Room Products
Prototyping Products
DE1
RF and RFID
View more