SC1211VXSTRT

Manufacturer Part NumberSC1211VXSTRT
Description
ManufacturerSEMTECH [Semtech Corporation]
SC1211VXSTRT datasheet
 


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POWER MANAGEMENT
Description
The SC1211VX is a high speed, Combi-Sense®, dual out-
put driver designed to drive high-side and low-side
MOSFETs in a synchronous Buck converter. These
drivers combined with Combi-Sense® PWM controllers,
such as Semtech SC2643VX or SC2643, provide a
cost effective multi-phase voltage regulator for advanced
microprocessors.
The Combi-Sense® is a technique to sense the inductor
current for peak current mode control of voltage regula-
tor without using sensing resistor. It provides the follow-
ing advantages:
- No costly precision sensing resistor
- Lossless current sensing
- High level noise free signal
- Fast response
- Suitable for wide range of duty cycle
- Only two small signal components (third optional)
The detailed explanation of the technique can be found
in the Applications Information section.
A 30ns max propagation delay from input transition to
the gate of the power FET’s guarantees operation at high
switching frequencies. Internal overlap protection circuit
prevents shoot-through from Vin to PGND in the main
and synchronous MOSFETs. The adaptive overlap pro-
tection circuit ensures the bottom FET does not turn on
until the top FET source has reached 1V, to prevent cross-
conduction.
High current drive capability allows fast switching, thus
reducing switching losses at high (up to 1.5MHz) frequen-
cies without causing thermal stress on the driver.
Under-voltage-lockout and over-temperature shutdown
features are included for proper and safe operation.
Timed latches and improved robustness are built into
the housekeeping functions such as the Under Voltage
Lockout and adaptive Shoot-through protection circuitry
to prevent false triggering and to assure safe operation.
The SC1211VX is offered in a Power SOIC-8L package.
October 12, 2005
High Speed, Combi-Sense
MOSFET Driver for Mobile Applications
Features
u
High efficiency
u
High peak drive current
u
Adaptive non-overlapping gate drives provide
shoot-through protection
u
Support
and VID-on-fly operations
Combi-Sense®
u
Fast rise and fall times (15ns typical with 3000pf
load)
u
Ultra-low (<30ns) propagation delay (BG going low)
u
Floating top gate drive
u
Crowbar function for over voltage protection
u
High frequency (to 1.5 MHz) operation allows use
of small inductors and low cost ceramic capacitors
u
Under-voltage-lockout
u
Low quiescent current
u
Power SOIC-8L package, fully RoHS and WEEE
compliant
Applications
u
Intel Pentium
processor power supplies
®
u
AMD Athlon
TM
and AMD-K8
supplies
u
High efficiency portable and notebook computer
u
Battery powered application
u
High current low voltage DC-DC converter
1
®
, Synchronous
processor power
TM
s
s
s
www.semtech.com

SC1211VXSTRT Summary of contents

  • Page 1

    POWER MANAGEMENT Description The SC1211VX is a high speed, Combi-Sense®, dual out- put driver designed to drive high-side and low-side MOSFETs in a synchronous Buck converter. These drivers combined with Combi-Sense® PWM controllers, such as Semtech SC2643VX or SC2643, provide ...

  • Page 2

    POWER MANAGEMENT Typical Application Circuit Vin (+12V) PWM Vcc (+5V) Inductor Curr ent Signal 2005 Semtech Corp 1uF 1N4148 R1 1R0 9 PGND U1 SC1211V 1uF R2 2 SC1211VX Vout ...

  • Page 3

    POWER MANAGEMENT Absolute Maximum Ratings Exceeding the specifications below may result in permanent damage to the device, or device malfunction. Operation outside of the parameters specified in the Electrical Characteristics section is not implied ...

  • Page 4

    POWER MANAGEMENT Electrical Characteristics (Cont.) Unless specified 25° ...

  • Page 5

    POWER MANAGEMENT Timing Diagrams CO DRN PDL_BG Rising Edge Transition 2005 Semtech Corp PDH_TG R_TG 1.4V F_BG 5 SC1211VX 1. PDL_TG F_TG t t PDH_BG R_BG Falling Edge Transition www.semtech.com ...

  • Page 6

    ... Semtech Corp. Ordering Information Note: 7 VCC (1) Only available in tape and reel packaging. A reel contains 2500 devices. 6 VIN (2). SC1211VXSTRT is lead free part. 5 VPN ...

  • Page 7

    POWER MANAGEMENT Block Diagram VCC CO PGND 2005 Semtech Corp. LOGIC UVLO CONTROL & OVERLAP PROT ECTION CIRCUIT 7 SC1211VX VIN VPN BST TG DRN BG www.semtech.com ...

  • Page 8

    POWER MANAGEMENT Applications Information THEOR THEORY OF OPERA THEOR Y OF OPERA Y OF OPERATION Y OF OPERA TION TION TION THEOR THEOR Y OF OPERA TION The SC1211VX is a high speed, Combi-Sense®, dual out- put driver designed to ...

  • Page 9

    POWER MANAGEMENT Applications Information (Cont.) VPN and Vout. During Q1 turn-on, Qcst turns on as well. The voltage drop across Q1 and Lo charges Ccs. During Q2 turn-on, Qcsb turns on as well. The voltage drop across Q2 and Lo ...

  • Page 10

    POWER MANAGEMENT Applications Information (Cont.) whole during PCB layout. Refer to Semtech SC2643VX/ SC1211VX EVB Layout Guideline. For the SC1211VX driver, the following guidelines are typically recommended during PCB layout: 1. Place the SC1211VX close to the FETs for shortest ...

  • Page 11

    POWER MANAGEMENT Outline Drawing - Power SOIC-8 Outline Drawing - Power SOIC-8L Land Pattern - Power SOIC-8 Contact Information 2005 Semtech Corp. Semtech Corporation Power Management Products Division 200 Flynn Rd., Camarillo, CA 93012 Phone: (805)498-2111 FAX (805)498-3804 11 SC1211VX ...