DataSheet.jp

ADM1051A の電気的特性と機能

ADM1051AのメーカーはAnalog Devicesです、この部品の機能は「Precision Dual Voltage Regulator Controllers」です。


製品の詳細 ( Datasheet PDF )

部品番号 ADM1051A
部品説明 Precision Dual Voltage Regulator Controllers
メーカ Analog Devices
ロゴ Analog Devices ロゴ 




このページの下部にプレビューとADM1051Aダウンロード(pdfファイル)リンクがあります。

Total 10 pages

No Preview Available !

ADM1051A Datasheet, ADM1051A PDF,ピン配置, 機能
a
Precision Dual Voltage
Regulator Controllers
ADM1051/ADM1051A
FEATURES
Two Independent Controllers on One Chip
1.515 V and 1.818 V Outputs
Shutdown Inputs to Control Each Channel
Compatible with PC Motherboard TYPEDET Signal
؎2.5% Accuracy Over, Line, Load, and Temperature
Low Quiescent Current
Low Shutdown Current
Works with External N-Channel MOSFETs for Low Cost
“Hiccup Mode” Fault Protection
No External Voltage or Current Setting Resistors
1.8 V/3.3 V ICH Sequenced Power-Up on ADM1051A
Small, 8-Lead SOIC Package
APPLICATIONS
Desktop Computers
Servers
Workstations
GENERAL DESCRIPTION
The ADM1051/ADM1051A are dual, precision, voltage regula-
tor controllers intended for power rail generation and active bus
termination on personal computer motherboards. They contain a
precision 1.2 V bandgap reference and two channels consisting of
control amplifiers driving external power devices. Each channel
has a shutdown input to turn off amplifier output and Hiccup
Mode protection circuitry for the external power device. The
shutdown input on the 1.5 V channel can also be used with the
TYPEDET signal on a PC motherboard to select the output voltage.
The ADM1051/ADM1051A operate from a 12 V supply, which
gives sufficient headroom for the amplifiers to drive external
N-channel MOSFETs, operating as source-followers, as the
external series pass devices. This has the advantage that N-
channel devices are cheaper than P-channel devices of similar
performance, and the circuit is easier to stabilize than one using
P-channel devices in a common-source configuration.
SHDN1
SHDN2
FUNCTIONAL BLOCK DIAGRAM
VCC
ADM1051/ADM1051A
BANDGAP
REFERENCE
CONTROL
AMPLIFIER
FORCE 1
VCC SENSE 1
50A
SHUTDOWN
CONTROL
HICCUP
COMPARATOR
VCC
50A
VCC
POWER-ON
RESET
NO CONNECTION
ON ADM1051A
CONTROL
AMPLIFIER
FORCE 2
SENSE 2
SHUTDOWN
CONTROL
HICCUP
COMPARATOR
CLK/DELAY
GENERATOR
CLOCK
OSCILLATOR
VIN
3.3V
100F
VOUT1
2؋100F
VIN
3.3V
100F
VOUT2
2؋100F
GND
REV. 0
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700 World Wide Web Site: http://www.analog.com
Fax: 781/326-8703
© Analog Devices, Inc., 2000

1 Page





ADM1051A pdf, ピン配列
ADM1051/ADM1051A
ABSOLUTE MAXIMUM RATINGS*
(TA = 25°C unless otherwise noted)
VCC to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 V
SHDN1, SHDN2 to GND . . . . . . . . –0.3 V to (VCC + 0.3 V)
SENSE 1, SENSE 2 to GND . . . . . . . . . . . –0.3 V to +5.5 V
FORCE 1, FORCE 2 . . . . . . . Short-Circuit to GND or VCC
Continuous Power Dissipation (TA = 70°C) . . . . . . . 650 mW
8-Lead SOIC (Derate 8.3 mW/°C Above 70°C)
Operating Temperature Range
Commercial (J Version) . . . . . . . . . . . . . . . . . . 0°C to 70°C
Storage Temperature Range . . . . . . . . . . . –65°C to +150°C
Lead Temperature (Soldering, 10 sec) . . . . . . . . . . . . 300°C
*This is a stress rating only; functional operation of the device at these or any other
conditions above those indicated in the operation sections of this specification is
not implied. Exposure to absolute maximum rating conditions for extended
periods of time may affect reliability.
THERMAL CHARACTERISTICS
8-Lead Small Outline Package:
θJA = 150°C/W
ORDERING GUIDE
Model
ADM1051JR
ADM1051AJR
Temperature
Range
0°C to 70°C
0°C to 70°C
Package
Description
8-Lead SOIC
8-Lead SOIC
Package
Option
R-8
R-8
PIN FUNCTION DESCRIPTIONS
Pin
No. Mnemonic Function
1 FORCE 2 Output of Channel 2 control amplifier
to gate of external N-channel MOSFET.
2 SENSE 2 Input from source of external MOSFET
to inverting input of Channel 2 control
amplifier, via output voltage-setting
feedback resistor network.
3 SHDN2 Digital Input. Active-low shutdown
control with 50 µA internal pull-up. The
output of Channel 2 control amplifier goes
to ground when SHDN2 is taken low.
4 GND
5 SHDN1
Device Ground Pin.
Digital Input. Active-low shutdown con-
trol with 50 µA internal pull-up. See text for
more details of SHDN1 functionality.
6 SENSE 1 Input from source of external MOSFET to
inverting input of Channel 1 control ampli-
fier, via output voltage-setting feedback
resistor network.
7 FORCE 1 Output of Channel 1 control amplifier to
gate of external N-channel MOSFET.
8 VCC
12 V Supply.
12V
VCC
VIN
1F 3.3V
PHD55N03LT
FORCE 1
100F
LEAVE OPEN OR
CONNECT TO
LOGIC SIGNALS
IF SHUTDOWN
REQUIRED
SHDN1
SHDN2
ADM1051/
ADM1051A
SENSE 1
VIN
3.3V
MTD3055VL
FORCE 2
VOUT1
2؋100F
100F
SENSE 2
VOUT2
2؋100F
Figure 1. Test Circuit
PIN CONFIGURATION
FORCE 2 1
8 VCC
SENSE 2 2 ADM1051/ 7 FORCE 1
ADM1051A
SHDN2 3 TOP VIEW 6 SENSE 1
GND 4 (Not to Scale) 5 SHDN1
CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection.
Although the ADM1051/ADM1051A features proprietary ESD protection circuitry, permanent
damage may occur on devices subjected to high-energy electrostatic discharges. Therefore,
proper ESD precautions are recommended to avoid performance degradation or loss of
functionality.
WARNING!
ESD SENSITIVE DEVICE
REV. 0
–3–


3Pages


ADM1051A 電子部品, 半導体
ADM1051/ADM1051A
1.855
VCH2 V's 5VSB ILOAD؍500m
1.805
1.755
1.705
70؇C
1.655
1.605
1.555
1.505
25؇C
0؇C
1.455
1.405
1.355
1.305
3.7 3.9 4.1 4.3
4.5 4.7 4.9
5.1 5.3
5VSB V
TPC 13. ADM1051A Channel 2 Output Voltage vs. 5 VSB
Voltage. Test Circuit as Figure 7, ILOAD = 500 mA
1.855
VCH2 V's 5VSB ILOAD؍1
1.805
1.755
1.705
70؇C
1.655
1.605
1.555
1.505
25؇C
0؇C
1.455
1.405
1.355
1.305
3.7 3.9 4.1 4.3
4.5 4.7 4.9 5.1 5.3
5VSB V
TPC 14. ADM1051A Channel 2 Output Voltage vs. 5 VSB
Voltage. Test Circuit as Figure 7, ILOAD = 1 A
GENERAL DESCRIPTION
The ADM1051/ADM1051A are dual, precision, voltage regulator
controllers intended for power rail generation and active bus ter-
mination in AGP and ICH applications on personal computer
motherboards. They contain a precision 1.2 V bandgap ref-
erence and two almost identical channels consisting of control
amplifiers driving external power devices. The main difference
between the two channels is the regulated output voltage, defined
by the resistor ratios on the voltage sense inputs of each channel.
Channel 1 has an output of nominally 1.515 V, but can be
switched to a 3.3 V output, while Channel 2 has a nominal
output of 1.818 V. Channel 1 is also optimized for driving
MOSFETs with lower on-resistance and higher gate capaci-
tance, as explained later.
Each channel has a shutdown input to turn off amplifier output
and protection circuitry for the external power device. The
shutdown input of Channel 1 has additional functionality as
described later.
The ADM1051A has some minor differences from the ADM1051
to support power-supply sequencing and voltage requirements
of some I/O control hub chipsets, which dictate that the 1.818 V
rail must never be more than 2 V below the 3.3 V rail.
The ADM1051/ADM1051A operates from a 12 V VCC supply.
The outputs are disabled until VCC climbs above the Power-On
Reset threshold (6 V–9 V). POR does not apply to Channel 2 of
the ADM1051A. This output will begin to rise as soon as there
is sufficient gate drive to turn on the external MOSFET.
The outputs from the ADM1051/ADM1051A are used to drive
external N-channel MOSFETs, operating as source-followers.
This has the advantage that N-channel devices are cheaper than
P-channel devices of similar performance, and the circuit is easier
to stabilize than one using P-channel devices in a common-
source configuration.
The external power devices are protected by a “Hiccup Mode”
circuit that operates if the circuit goes out of regulation due to
an output short-circuit. In this case the power device is pulsed
on/off with a 1:40 duty-cycle to limit the power dissipation until
the fault condition is removed. Again, to prevent Channel 2
falling more than 2 V below Channel 1, Hiccup Mode does not
operate on Channel 2 of the ADM1051A.
CIRCUIT DESCRIPTION
CONTROL AMPLIFIERS
The reference voltage is amplified and buffered by the control
amplifiers and external MOSFETs, the output voltage of each
channel being determined by the feedback resistor network
between the sense input and the inverting input of the control
amplifier.
The two control amplifiers in the ADM1051/ADM1051A are
almost identical, apart, from the ratios of the feedback resistor
networks on the sense inputs. A power-on reset circuit disables
the amplifier output until VCC has risen above the reset thresh-
old (not Channel 2 of ADM1051A).
Each amplifier output drives the gate of an N-channel power
MOSFET, whose drain is connected to the unregulated supply
input and whose source is the regulated output voltage, which is
also fed back to the appropriate sense input of the ADM1051/
ADM1051A. The control amplifiers have high current-drive
capability so they can quickly charge and discharge the gate
capacitance of the external MOSFET, thus giving good transient
response to changes in load or input voltage. In particular,
Channel 1 is optimized to drive MOSFETs with very low on
resistance and correspondingly higher gate capacitance such as
the PHD55N03LT from Philips. This is to minimize voltage
drop across the MOSFET when Channel 1 is used in 3.3 V
mode, as explained later.
SHUTDOWN INPUTS AND TYPEDET COMPATIBILITY
Each channel has a separate shutdown input, which may be
controlled by a logic signal, and allows the output of the regula-
tor to be turned on or off. If the shutdown input is held high or
not connected, the regulator operates normally. If the shutdown
input is held low, the enable input of the control amplifier is turned
off and the amplifier output goes low, turning off the regulator.
The SHDN1 input on Channel 1 has additional functionality that
can be controlled by the TYPEDET signal on PC motherboards.
The AGP bus on a PC motherboard can have two different modes
of operation, requiring different regulated voltages of 3.3 V or
1.5 V. These two modes are signaled by the TYPEDET signal on
the PC motherboard, as follows:
TYPEDET = 0 V – Regulated Voltage 1.5 V (4× AGP Graphics)
TYPEDET Floating – Regulated Voltage 3.3 V (2× AGP Graphics)
–6– REV. 0

6 Page



ページ 合計 : 10 ページ
 
PDF
ダウンロード
[ ADM1051A データシート.PDF ]


データシートを活用すると、その部品の主な機能と仕様を詳しく理解できます。 ピン構成、電気的特性、動作パラメータ、性能を確認してください。


共有リンク

Link :


部品番号部品説明メーカ
ADM1051

Precision Dual Voltage Regulator Controllers

Analog Devices
Analog Devices
ADM1051A

Precision Dual Voltage Regulator Controllers

Analog Devices
Analog Devices


www.DataSheet.jp    |   2020   |  メール    |   最新    |   Sitemap