參數(shù)資料
型號： PGA308AIDGSR
廠商： TEXAS INSTRUMENTS INC
元件分類： 模擬信號調(diào)理
英文描述： SPECIALTY ANALOG CIRCUIT, PDSO10
封裝： GREEN, PLASTIC, MSOP-10
文件頁數(shù)： 9/29頁
文件大?。?/td> 962K
代理商： PGA308AIDGSR
www.ti.com
SBOS440B – JULY 2008 – REVISED DECEMBER 2010
Timeout on the One-Wire Interface
ONE-WIRE OPERATION WITH 1W
CONNECTED TO VOUT
The PGA308 includes a timeout mechanism. If
synchronization
between
the
controller
and
the
In some sensor applications, it is desired to provide
PGA308
is
lost
for
any
reason,
the
timeout
the end user of the sensor module with three pins:
mechanism allows the One-Wire interface to reset
VS, GND, and Sensor Out. It is also desired in these
communication.
The
timeout
period
is
set
to
applications to digitally calibrate the sensor module
approximately 28ms (typical). If the timeout period
after its final assembly of sensor and electronics. The
expires between the initialization byte and the
PGA308 has a mode that allows the One-Wire
command byte, between the command byte and any
interface pin (1W) to be tied directly to the PGA308
data byte, or between any data bytes, the PGA308
output pin (VOUT).
resets the One-Wire interface circuitry so that it
To calibrate the PGA308 in Three-Wire configuration,
expects an initialization byte. Every time that a byte is
program the internal registers and measure the
transmitted on the single wire interface, this timeout
resulting VOUT. To do this while VOUT is connected to
period restarts.
1W requires the ability to enable and disable VOUT.
Thus, the 1W/VOUT line operates in a multiplexed
POWER-ON SEQUENCE
mode where 1W is used as a bidirectional digital
The PGA308 provides circuitry to detect when the
interface while VOUT is disabled, and VOUT drives the
power supply is applied to the PGA308 and resets
line as a conditioned sensor output voltage when it is
the internal registers to a known power-on reset
enabled.
(POR) state. This reset also occurs whenever the
The PGA308 also provides a mode in which the
supply is invalid so that the PGA308 is set to a known
output amplifier can be enabled for a set time period
state when the supply becomes valid again. The
and then disabled again to allow sharing of the 1W
threshold for this circuit is approximately 1.7V to
pin
with
the
VOUT connection. This action is
2.1V. After the power supply becomes valid, the
accomplished by writing a value to bits OEN[7:0] in
PGA308 waits for approximately 25ms, during which
the One-Wire Enable Control register (OENC). Any
VOUT is disabled, and then attempts to read the data
non-zero value enables the output. This non-zero
from the last valid OTP memory bank. If the memory
value is decremented every 10ms until it becomes
bank has the proper checksum, then the PGA308
zero. When this value becomes zero, VOUT is
RAM is loaded with the OTP data and VOUT enabled.
disabled and a 1s timeout begins waiting for bus
If the checksum is invalid, VOUT is set to disabled.
activity on the digital interface (1W pin). As long as
Unless disabled by the OWD bit in Configuration
there is activity on the 1W pin, the 1s timeout is
Register 2 (CFG2), the One-Wire interface can
continually reset. After 1s of no bus activity, the
always communicate to the PGA308 and override the
PGA308 checks for a correct checksum. If the
contents of the current RAM in use by setting the
checksum is correct, the PGA308 runs with the
appropriate SWL[2:0] bits in the Software Control
values that currently exist in RAM. If the checksum is
Register
(SFTC).
For
applications
that
require
not valid, the PGA308 checks for written bank select
instant-on for VOUT, the NOW bit in the CFG2 register
registers in OTP in the order of BANK SEL4, BANK
can be set to '1', which eliminates the 25ms disable
SEL3, BANK SEL2 then BANK SEL1. The highest
of VOUT on power-up.
bank select register containing valid programmed
space
data is read. The value read from this register points
to one of the seven OTP banks, which is then loaded
space
into RAM.
space
Copyright 2008–2010, Texas Instruments Incorporated
17
Product Folder Link(s): PGA308
相關(guān)PDF資料
PDF描述
PGA308AIDGST SPECIALTY ANALOG CIRCUIT, PDSO10
PGA308AIDGSTG4 SPECIALTY ANALOG CIRCUIT, PDSO10
PGA309AIPWRG4 SPECIALTY ANALOG CIRCUIT, PDSO16
PGA309AIPWT SPECIALTY ANALOG CIRCUIT, PDSO16
PGA309AIPWR SPECIALTY ANALOG CIRCUIT, PDSO16
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
PGA308AIDGSRG4 功能描述:電流靈敏放大器 Sgl Amp w/Program- mable Gain RoHS:否 制造商:Texas Instruments 通道數(shù)量: 共模抑制比（最小值）:110 dB 輸入補償電壓:80 uV 電源電壓-最大:5.5 V 電源電壓-最小:2.7 V 電源電流:350 uA 最大工作溫度:+ 125 C 最小工作溫度:- 40 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-16 封裝:Reel
PGA308AIDGST 功能描述:電流靈敏放大器 Sgl Supply Auto-Zero Sensor Amp RoHS:否 制造商:Texas Instruments 通道數(shù)量: 共模抑制比（最小值）:110 dB 輸入補償電壓:80 uV 電源電壓-最大:5.5 V 電源電壓-最小:2.7 V 電源電流:350 uA 最大工作溫度:+ 125 C 最小工作溫度:- 40 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-16 封裝:Reel
PGA308AIDGST 制造商:Texas Instruments 功能描述:Instrumentation Amplifier IC
PGA308AIDGSTG4 功能描述:電流靈敏放大器 Sgl Amp w/Program- mable Gain RoHS:否 制造商:Texas Instruments 通道數(shù)量: 共模抑制比（最小值）:110 dB 輸入補償電壓:80 uV 電源電壓-最大:5.5 V 電源電壓-最小:2.7 V 電源電流:350 uA 最大工作溫度:+ 125 C 最小工作溫度:- 40 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-16 封裝:Reel
PGA308AIDRKR 功能描述:電流靈敏放大器 Sgl Supply Auto-Zero Sensor Amp RoHS:否 制造商:Texas Instruments 通道數(shù)量: 共模抑制比（最小值）:110 dB 輸入補償電壓:80 uV 電源電壓-最大:5.5 V 電源電壓-最小:2.7 V 電源電流:350 uA 最大工作溫度:+ 125 C 最小工作溫度:- 40 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-16 封裝:Reel
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。

采購需求

(若只采購一條型號，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購。也可以進入我的后臺，查看報價

發(fā)布成功！您可以繼續(xù)發(fā)布采購。也可以進入我的后臺，查看報價

*型號 *數(shù)量 廠商 批號 封裝
添加更多采購

我的聯(lián)系方式

*
*
*