參數(shù)資料
型號: MAX863EEE
廠商: MAXIM INTEGRATED PRODUCTS INC
元件分類: 穩(wěn)壓器
英文描述: Dual, High-Efficiency, PFM, Step-Up DC-DC Controller
中文描述: DUAL SWITCHING CONTROLLER, PDSO16
封裝: 0.150 INCH, 0.025 INCH PITCH, QSOP-16
文件頁數(shù): 5/16頁
文件大?。?/td> 194K
代理商: MAX863EEE
M
Dual, High-Effic ienc y, PFM, S tep-Up
DC-DC Controller
_______________________________________________________________________________________
5
_______________Detailed Desc ription
The MAX863 dual, bi-CMOS, step-up, switch-mode
power-supply controller provides preset 3.3V, 5V, or
adjustable outputs. Its pulse-frequency-modulated
(PFM) control scheme combines the advantages of low
supply current at light loads and high efficiency with
heavy loads. These attributes make the MAX863 ideal
for use in portable battery-powered systems where
small size and low cost are extremely important, and
where low quiescent current and high efficiency are
needed to maximize operational battery life. Use of
external current-sense resistors and MOSFETs allows
the designer to tailor the output current and voltage
capability for a diverse range of applications.
PFM Control S c heme
Each DC-DC controller in the MAX863 uses a one-shot-
sequenced, current-limited PFM design, as shown in
Figure 1. Referring to the Typical Operating Circuit
(Figure 2) and the switching waveforms (Figures 3a–3f),
the circuit works as follows. Output voltage is sensed
by the error comparator using either an internal voltage
divider connected to SENSE1 or an external voltage
divider connected to FB1. When the output voltage
drops, the error comparator sets an internal flip-flop.
The flip-flop turns on an external MOSFET, which allows
inductor current to ramp-up, storing energy in a mag-
netic field.
______________________________________________________________Pin Desc ription
PIN
Feedback Input for DC-DC Controller 1 in Fixed-Output Mode
SENSE1
1
FUNCTION
NAME
IC Power-Supply Input
V
DD
2
Bootstrap Low-Voltage-Oscillator Enable Input. BOOT is an active-high, logic-level input. It enables the
low-voltage oscillator to allow start-up from input voltages down to 1.5V while in a bootstrapped circuit
configuration. Connect BOOT to GND when in a non-bootstrapped configuration.
If BOOT is high, V
DD
must be connected to OUT1.
BOOT
4
Adjustable Feedback and Preset Output Voltage Selection Input for DC-DC Controller 1. Connect to V
DD
for 3.3V preset output or to GND for 5V output. Connect a resistor voltage divider to adjust the output volt-
age. See the section Set the Output Voltage.
FB1
3
Gate-Drive Output of DC-DC Controller 1. Drives an external N-channel power MOSFET.
EXT1
6
High-Current Ground Return for Internal MOSFET Drivers
PGND
8
Analog Ground for Internal Reference, Feedback, and Control Circuits
GND
7
Input to the Current-Sense Comparator of DC-DC Controller 1
CS1
5
Input to the Current-Sense Amplifier of DC-DC Controller 2
CS2
10
Adjustable Feedback Input for DC-DC Controller 2. Connect a resistor voltage divider to adjust the output
voltage. See the section Set the Output Voltage.
FB2
12
Active-Low Shutdown Input for DC-DC Controller 1. Connect to V
DD
for normal operation.
SHDN1
11
Low-Battery Comparator Input. When the voltage on LBI drops below 1.25V, LBO sinks current. If unused,
connect to GND.
LBI
14
Reference Bypass Input. Connect a 0.1μF ceramic capacitor from REF to GND.
REF
16
Active-Low Shutdown Input for DC-DC Controller 2. Connect to V
DD
for normal operation.
SHDN2
15
Low-Battery Output. An open-drain N-channel MOSFET output. Sinks current when the voltage on LBI
drops below 1.25V. If unused, connect to GND.
LBO
13
Gate-Drive Output of DC-DC Controller 2. Drives an external N-channel power MOSFET.
EXT2
9
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參數(shù)描述
MAX863EEE+ 功能描述:DC/DC 開關(guān)控制器 Dual PFM Step-Up DC/DC Controller RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK
MAX863EEE+T 功能描述:DC/DC 開關(guān)控制器 Dual PFM Step-Up DC/DC Controller RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK
MAX863EEE-T 功能描述:DC/DC 開關(guān)控制器 Dual PFM Step-Up DC/DC Controller RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK
MAX863EVKIT 功能描述:DC/DC 開關(guān)控制器 Evaluation Kit for the MAX863 RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK
MAX8640EVKIT 制造商:Maxim Integrated Products 功能描述:500MA 4MHZ/2MHZ SYNCHRONOUS STEP-D - Rail/Tube