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參數(shù)資料
| 型號： | L4985 |
| 文件頁數(shù)： | 1/23頁 |
| 文件大小： | 415K |
| 代理商： | L4985 |
L4985
HIGH EFFICIENCY SWITCHING REGULATOR
PRODUCT PREVIEW
OPERATINGINPUT VOLTAGE:
FROM4.5V TO 21V
HIGHEFFICIENCY3ASTEPDOWNCONVERTER
—
3A @ 3.3V OUTPUT VOLTAGE FROM 4.5V
INPUT VOLTAGE
—
ADJUSTABLE OUTPUT VOLTAGE
FROM 1.28V
—
GATE
DRIVER
FOR
RECTIFICATION
—
100% MAXIMUMDUTY CYCLE
—
INTERNAL CURRENT LIMIT
—
SOFT START, RESET SIGNAL,
THERMAL SHUTDOWN
AUXILIARY
CONVERTER
OPEN DRAIN SWITCH DELIVERING 5W
@ V
IN
= 12V
—
1.7A PEAKCURRENT INTERNALLY
LIMITED(TYP)
POWER MANAGEMENT
SYNCHRONOUS
WITH
40V
DESCRIPTION
This high efficiency DC-DC converter is a mono-
lithic device developed to generate all the volt-
ages required in multioutputs DC-DC converters,
in particular when the supply voltage is a battery,
and isolation is not needed.
Designed to start to operate at an inputvoltage as
low as 4.5V up to 21V, the device takes the ad-
vantages offered by our proprietary BCD Mul-
tipower technology to deliver 3A to the load on
the stepdown section, and to manage 1.5A peak
current on the open drain section.
The packagesproposed are in plastic dual in line,
Powerdip 20 (16+2+2) for standard assembly,
and SO20Lfor SMD assembly.
This device is constitueed by two major sections:
one section is a stepdown regulator, and the
other one is a flexible regulator with open drain
output DMOS transistor, source grounded, for fly-
back/forward topologies for multioutputs, or step-
up topologywhen a single voltage higher than the
supply one is requested.
Step Down Converter Section
The stepdownsection, delivering to the load up to
3A current, at an output voltage adjustable from
1.28V up to 16V,works in voltage mode, fixed fre-
quency,with no limitation on the maxduty cycle.
This section has been designed to maximise the
efficiency minimising the conduction losses and
the quiescentcurrent.
An internal step-up converter using a small chip
inductor and a filter capacitor provides voltage
and energy the gate driver of the internal N-chan-
nel DMOS transistor of 0.1
typ of R
dson
, and the
driver of an external DMOS transistor that should
require no more than 30nC of gate charge, at
100KHz.
The gate driver pin can be leftopen if the use of a
Schottkydiode is preferred.
An internal pulse by pulse current limiting protects
the device it self and the load from overload and
short circuit conditions.
A reset block, monitoring the feedback voltage,
with an programmable reset delay time, gener-
ates a reset signalfor the microprocessor.
The reset output is an opendrain.
Moreover, the DIS1 pin, active low, will inhibit the
whole device, reducing to leakage only the cur-
rent consumptionfrom the battery.
Thisis advancedinformation on a new productnow in developmentor undergoing evaluation. Details are subjectto change without notice.
March 1995
ORDERING NUMBERS:
L4985 (Powerdip)
L4985D (SO20)
POWERDIP 16+2+2
SO20
MULTIPOWER BCD TECHNOLOGY
1/23
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| L4985D | Voltage-Mode SMPS Controller |
| L4987CXX120 | VERY LOW DROP VOLTAGE REGULATOS WITH INHIBIT AND DROPOUT CONTROL FLAG |
| L4987CXX30 | VERY LOW DROP VOLTAGE REGULATOS WITH INHIBIT AND DROPOUT CONTROL FLAG |
| L4987CXX33 | VERY LOW DROP VOLTAGE REGULATOS WITH INHIBIT AND DROPOUT CONTROL FLAG |
| L4987CXX50 | VERY LOW DROP VOLTAGE REGULATOS WITH INHIBIT AND DROPOUT CONTROL FLAG |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| L4985D | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Voltage-Mode SMPS Controller |
| L4987 | 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:VERY LOW DROP VOLTAGE REGULATORS WITH INHIBIT AND DROPOUT CONTROL FLAG |
| L4987CPT120 | 功能描述:IC REG LDO 12V .2A P-PAK RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:2,500 系列:- 穩(wěn)壓器拓?fù)浣Y(jié)構(gòu):正，固定式 輸出電壓:3.1V 輸入電壓:最高 5.5V 電壓 - 壓降（標(biāo)準(zhǔn)）:- 穩(wěn)壓器數(shù)量:1 電流 - 輸出:300mA 電流 - 限制（最?。?420mA 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:SOT-23-5 細(xì)型，TSOT-23-5 供應(yīng)商設(shè)備封裝:TSOT-23-5 包裝:帶卷 (TR) |
| L4987CPT30 | 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:VERY LOW DROP VOLTAGE REGULATORS WITH INHIBIT AND DROPOUT CONTROL FLAG |
| L4987CPT33 | 功能描述:IC REG LDO 3.3V .2A P-PAK RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:2,500 系列:- 穩(wěn)壓器拓?fù)浣Y(jié)構(gòu):正，固定式 輸出電壓:3.1V 輸入電壓:最高 5.5V 電壓 - 壓降（標(biāo)準(zhǔn)）:- 穩(wěn)壓器數(shù)量:1 電流 - 輸出:300mA 電流 - 限制（最?。?420mA 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:SOT-23-5 細(xì)型，TSOT-23-5 供應(yīng)商設(shè)備封裝:TSOT-23-5 包裝:帶卷 (TR) |
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