參數(shù)資料
型號: LTC1426
廠商: Linear Technology Corporation
英文描述: 14-bit, 5V, 200KSPS, 4-Channel Unipolar ADC 20-TSSOP -40 to 85
中文描述: 微功率雙路6位PWM DAC的
文件頁數(shù): 6/8頁
文件大?。?/td> 222K
代理商: LTC1426
6
LTC1426
APPLICATIO
S I
N
FOR
ATIO
U
where V
PWM
is the no load DAC output voltage, R
L
is the
resistive load and R
OUT
is the DAC output impedance.
Therefore, the resistive load R
L
should be sufficiently large
to ignore the effect of output impedance on the load
voltage.
Figure 2 shows a typical lowpass filter recommended to
filter the PWM outputs. Without filtering, results obtained
from unfiltered outputs can be erroneous when taking
measurements from a voltmeter. The ratio of the filter time
constant, t, to the PWM frequency determines the amount
of output ripple frequency that feeds into the system. In
addition, the loading of the output also determines an
additional error voltage drop across R1.
W
U
power-up, then the chip configures in pulse mode until
the next V
CC
reset.
Figure 3 shows the simplified logic for determining the
interface mode at power-up. A set of pull-up/pull-down
resistors allow the LTC1426 to sense the state of the CLK
pins at power-up. If both CLK1 and CLK2 pins are floating
on power-up then the control signal from the LTC1426
leaves these resistors in place, allowing the LTC1426 to
detect three operating states at each CLK pin: high, low
and “middle” (floating). If the CLK pins are tied to either
logic 0 or 1 at power-up, then the control signal will
disconnect these resistors, making CLK1 and CLK2 CMOS
compatible input pins.
Note that both CLK pins will always be in the same mode.
If one pin is floating and the other is at logic high/low on
power-up, the LTC1426 will assume pulse mode.
TYPICAL APPLICATIO
N
S
N
Typical applications for this part include digital calibration,
industrial process control, automatic test equipment, cel-
lular telephones and portable battery-powered applications.
Figures 4 and 5 show how easy this part is to use. In all
applications, the PWM full-scale output voltage is set by
V
REF
. This makes interfacing convenient when a variety of
reference spans are needed.
Pulse Mode
Figure 4 shows the LTC1426 in a pulse mode, stand-alone
application. The LTC1426 can interface directly with
minimum external components to most popular micro-
Figure 4. Stand-Alone Pulse Mode Interface
processors (MPUs).
The Intel 8051 was chosen to dem-
onstrate direct interface for the LTC1426, as this
1
2
3
4
8
7
6
5
CLK1
CLK2
GND
PWM1
SHDN
V
CC
V
REF
PWM2
P1.0
P1.1
LTC1426
MPU
(e.g. 8051)
PWM1
1426 F04
PWM2
PWM1/PWM2: 0V TO 0.985(V
REF
)
0.1
μ
F
V
0V TO 5.5V
V
2.7V TO 5.5V
SHDN
Figure 2. Lowpass Filter for PWM Averaging
C1
0.1
μ
F
INPUT
OUTPUT
1426 F02
R1
10k
Digital Interface
The LTC1426 can be controlled by using one of two
interface modes: pulse mode and pushbutton mode. The
operating interface mode is determined during power-
up. If both CLK1 and CLK2 inputs are floating on power-up,
then an interface mode detect circuit configures the chip
in pushbutton mode until the next V
CC
reset (Figure 3).
However, if either of CLK1 or CLK2 is at logic 0 or 1 at
Figure 3. Interface Mode Detect Circuit
CLK1
CLK2
V
CC
CLK1 INPUT
CLK2 INPUT
CONTROL
LTC1426
1426 F03
INTERNAL LOGIC
相關(guān)PDF資料
PDF描述
LTC1426C Micropower Dual 6-Bit PWM DAC
LTC1426CMS8 Micropower Dual 6-Bit PWM DAC
LTC1426CS8 14-Bit 200KSPS ADC Serial Out, Auto PWRDN, Pseudo Differential Input 8-SOIC -40 to 85
LTC1426I Micropower Dual 6-Bit PWM DAC
LTC1426IS8 14-Bit 200KSPS ADC Serial Out, Auto PWRDN, Pseudo Differential Input 8-MSOP -40 to 85
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LTC1426CMS8 功能描述:IC PWM D/A CONV 6BIT DUAL 8-MSOP RoHS:否 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 數(shù)模轉(zhuǎn)換器 系列:- 產(chǎn)品培訓(xùn)模塊:LTC263x 12-, 10-, and 8-Bit VOUT DAC Family 特色產(chǎn)品:LTC2636 - Octal 12-/10-/8-Bit SPI VOUT DACs with 10ppm/°C Reference 標(biāo)準(zhǔn)包裝:91 系列:- 設(shè)置時(shí)間:4µs 位數(shù):10 數(shù)據(jù)接口:MICROWIRE?,串行,SPI? 轉(zhuǎn)換器數(shù)目:8 電壓電源:單電源 功率耗散(最大):2.7mW 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:14-WFDFN 裸露焊盤 供應(yīng)商設(shè)備封裝:14-DFN-EP(4x3) 包裝:管件 輸出數(shù)目和類型:8 電壓,單極 采樣率(每秒):*
LTC1426CMS8#PBF 功能描述:IC PWM D/A CONV 6BIT DUAL 8-MSOP RoHS:是 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 數(shù)模轉(zhuǎn)換器 系列:- 標(biāo)準(zhǔn)包裝:2,400 系列:- 設(shè)置時(shí)間:- 位數(shù):18 數(shù)據(jù)接口:串行 轉(zhuǎn)換器數(shù)目:3 電壓電源:模擬和數(shù)字 功率耗散(最大):- 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:36-TFBGA 供應(yīng)商設(shè)備封裝:36-TFBGA 包裝:帶卷 (TR) 輸出數(shù)目和類型:* 采樣率(每秒):*
LTC1426CMS8#TR 功能描述:IC DAC PWM 6BIT DUAL MCPWR 8MSOP RoHS:否 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 數(shù)模轉(zhuǎn)換器 系列:- 產(chǎn)品培訓(xùn)模塊:LTC263x 12-, 10-, and 8-Bit VOUT DAC Family 特色產(chǎn)品:LTC2636 - Octal 12-/10-/8-Bit SPI VOUT DACs with 10ppm/°C Reference 標(biāo)準(zhǔn)包裝:91 系列:- 設(shè)置時(shí)間:4µs 位數(shù):10 數(shù)據(jù)接口:MICROWIRE?,串行,SPI? 轉(zhuǎn)換器數(shù)目:8 電壓電源:單電源 功率耗散(最大):2.7mW 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:14-WFDFN 裸露焊盤 供應(yīng)商設(shè)備封裝:14-DFN-EP(4x3) 包裝:管件 輸出數(shù)目和類型:8 電壓,單極 采樣率(每秒):*
LTC1426CMS8#TRPBF 功能描述:IC PWM D/A CONV 6BIT DUAL 8-MSOP RoHS:是 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 數(shù)模轉(zhuǎn)換器 系列:- 標(biāo)準(zhǔn)包裝:2,400 系列:- 設(shè)置時(shí)間:- 位數(shù):18 數(shù)據(jù)接口:串行 轉(zhuǎn)換器數(shù)目:3 電壓電源:模擬和數(shù)字 功率耗散(最大):- 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:36-TFBGA 供應(yīng)商設(shè)備封裝:36-TFBGA 包裝:帶卷 (TR) 輸出數(shù)目和類型:* 采樣率(每秒):*
LTC1426CS8 功能描述:IC PWM D/A CONV 6BIT DUAL 8-SOIC RoHS:否 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 數(shù)模轉(zhuǎn)換器 系列:- 產(chǎn)品培訓(xùn)模塊:LTC263x 12-, 10-, and 8-Bit VOUT DAC Family 特色產(chǎn)品:LTC2636 - Octal 12-/10-/8-Bit SPI VOUT DACs with 10ppm/°C Reference 標(biāo)準(zhǔn)包裝:91 系列:- 設(shè)置時(shí)間:4µs 位數(shù):10 數(shù)據(jù)接口:MICROWIRE?,串行,SPI? 轉(zhuǎn)換器數(shù)目:8 電壓電源:單電源 功率耗散(最大):2.7mW 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:14-WFDFN 裸露焊盤 供應(yīng)商設(shè)備封裝:14-DFN-EP(4x3) 包裝:管件 輸出數(shù)目和類型:8 電壓,單極 采樣率(每秒):*