Rainbow-electronics MAX1636 Manual do Utilizador Página 1

General DescriptionThe MAX1636 is a synchronous, buck, switch-mode,power-supply controller that generates the CPU supplyvoltage in battery-powered sys

IRC (1) 512-992-3377 (512) 992-7900Detailed DescriptionThe MAX1636 is a BiCMOS, switch-mode, power-sup-ply controller designed primarily for buck-topo

MAX1636Low-Voltage, Precision Step-DownController for Portable CPU Power______________________________________________________________________________

PWM ControllerThe heart of the current-mode PWM controller is amulti-input, open-loop comparator that sums four sig-nals: the output voltage error sig

MAX1636Low-Voltage, Precision Step-DownController for Portable CPU Power______________________________________________________________________________

MAX1636REF and VL Supplies and VCCInputThe 1.1V reference (REF) is accurate to ±1% over tem-perature, making REF useful as a precision system ref-eren

Output Overvoltage Protection (OVP)The overvoltage crowbar protection circuit is intendedto blow a fuse in series with the battery if the mainSMPS out

MAX1636Ringing at the high-side MOSFET gate (DH) in discon-tinuous-conduction mode (light loads) is a natural oper-ating condition. It is caused by re

Adjustable-Output Feedback(Dual-Mode FB) A fixed, preset output voltage of 2.5V and 3.3V isselected when FB is connected to VCCor ground. Inthis mode,

MAX1636Design ProcedureThe five predesigned standard application circuits(Figure 1 and Table 1) contain ready-to-use solutionsfor common application n

determined by the input voltage and load current, withthe worst case occurring at VIN= 2 x VOUT:Therefore, when VINis 2 x VOUT:IRMS= ILOAD/ 2Output Fi

mVMAX1636Low-Voltage, Precision Step-DownController for Portable CPU Power2 __________________________________________________________________________

MAX1636Low-Voltage, Precision Step-DownController for Portable CPU Power20 ___________________________________________________________________________

where RDCis the DC resistance of the coil, RDS(ON)isthe MOSFET on-resistance, and RSENSEis the current-sense resistor value. The RDS(ON) term assumes

MAX1636connections, the bottom layer for quiet connections(REF, CC, GND), and the inner layers for an uninter-rupted ground plane. Use the following s

MAX1636Low-Voltage, Precision Step-DownController for Portable CPU Power______________________________________________________________________________

MAX1636Low-Voltage, Precision Step-DownController for Portable CPU Power______________________________________________________________________________

MAX1636Low-Voltage, Precision Step-DownController for Portable CPU Power4 ____________________________________________________________________________

MAX1636Low-Voltage, Precision Step-DownController for Portable CPU Power______________________________________________________________________________

5010075150125225200175250150 250200 300 350 400 450 500MAX1636 TOC11FOSC (kHz)RESET TIME DELAY (ms)RESET TIME DELAYvs. OSC FREQUENCYVOUT50mV/divLOADCU

MAX1636Low-Voltage, Precision Step-DownController for Portable CPU Power______________________________________________________________________________

MAX1636Low-Voltage, Precision Step-DownController for Portable CPU Power8 ____________________________________________________________________________

MAX1636Low-Voltage, Precision Step-DownController for Portable CPU Power______________________________________________________________________________