參數(shù)資料
型號: ADUC845
廠商: Analog Devices, Inc.
元件分類: ADC
英文描述: MicroConverter Multichannel 24-/16-Bit ADCs with Embedded 62 kB Flash and Single-Cycle MCU
中文描述: MicroConverter的多通道ADC的24-/16-Bit與嵌入式62 kB閃存以及單周期控制器
文件頁數(shù): 55/108頁
文件大?。?/td> 1109K
代理商: ADUC845
ADuC845/ADuC847/ADuC848
Rev. A | Page 55 of 108
SOURCE/SINK CURRENT (mA)
3
0
5
10
15
O
2
1
0
DAC LOADED WITH 0000H
DAC LOADED WITH 0FFFH
0
Figure 36. Source and Sink Current Capability with V
REF
= AV
DD
= 3 V
For larger loads, the current drive capability may not be sufficient.
To increase the source and sink current capability of the DAC,
an external buffer should be added as shown in Figure 37.
ADuC845/
ADuC847/
ADuC848
DAC
0
14
Figure 37. Buffering the DAC Output
The internal DAC output buffer also features a high impedance
disable function. In the chip’s default power-on state, the DAC is
disabled and its output is in a high impedance state (or three-
state) where it remains inactive until enabled in software. This
means that if a zero output is desired during power-on or
power-down transient conditions, a pull-down resistor must be
added to each DAC output. Assuming that this resistor is in
place, the DAC output remains at ground potential whenever
the DAC is disabled.
PULSE-WIDTH MODULATOR (PWM)
The ADuC845/ADuC847/ADuC848 has a highly flexible PWM
offering programmable resolution and an input clock. The
PWM can be configured in six different modes of operation.
Two of these modes allow the PWM to be configured as a Σ-
DAC with up to 16 bits of resolution. A block diagram of the
PWM is shown in Figure 38.
CLOCK
PRODIVIDER
COMPARE
MODE
PWM0H/L
PWM1H/L
12.583MHz (F
VCO)
EXTERNAL CLOCK ON P2.7
32.768kHz/15
32.768kHz (F
XTAL)
P2.5
P2.6
16-BIT PWM COUNTER
0
Figure 38. PWM Block Diagram
The PWM uses control SFR, PWMCON, and four data SFRs:
PWM0H, PWM0L, PWM1H, and PWM1L.
PWMCON (as described in Table 34) controls the different
modes of operation of the PWM as well as the PWM clock
frequency. PWM0H/L and PWM1H/L are the data registers that
determine the duty cycles of the PWM outputs at P2.5 and P2.6.
To use the PWM user software, first write to PWMCON to
select the PWM mode of operation and the PWM input clock.
Writing to PWMCON also resets the PWM counter. In any of
the 16-bit modes of operation (Modes 1, 3, 4, 6), user software
should write to the PWM0L or PWM1L SFRs first. This value is
written to a hidden SFR. Writing to the PWM0H or PWM1H
SFRs updates both the PWMxH and the PWMxL SFRs but does
not change the outputs until the end of the PWM cycle in
progress. The values written to these 16-bit registers are then
used in the next PWM cycle.
相關(guān)PDF資料
PDF描述
ADUC845BCP8-3 MicroConverter Multichannel 24-/16-Bit ADCs with Embedded 62 kB Flash and Single-Cycle MCU
ADUC847BCP8-3 MicroConverter Multichannel 24-/16-Bit ADCs with Embedded 62 kB Flash and Single-Cycle MCU
ADUC845BCP8-5 MicroConverter Multichannel 24-/16-Bit ADCs with Embedded 62 kB Flash and Single-Cycle MCU
ADUC847BCP8-5 MicroConverter Multichannel 24-/16-Bit ADCs with Embedded 62 kB Flash and Single-Cycle MCU
ADUC845BCP62-3 MicroConverter Multichannel 24-/16-Bit ADCs with Embedded 62 kB Flash and Single-Cycle MCU
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
ADUC845_12 制造商:AD 制造商全稱:Analog Devices 功能描述:MicroConverter?? Multichannel 24-/16-Bit ADCs with Embedded 62 kB Flash and Single-Cycle MCU
ADUC845BCP32-3 制造商:Analog Devices 功能描述:10 CHANNEL 24 BIT DUAL ADC + FAST 8BIT UP - Trays
ADUC845BCP32-5 制造商:Analog Devices 功能描述:10 CHANNEL 24 BIT DUAL ADC + FAST 8BIT UP - Trays
ADUC845BCP62-3 制造商:Analog Devices 功能描述:MCU 8-bit ADuC8xx 8052 CISC 62KB Flash 3.3V/5V 56-Pin LFCSP EP
ADUC845BCP62-5 制造商:AD 制造商全稱:Analog Devices 功能描述:MicroConverter Multichannel 24-/16-Bit ADCs with Embedded 62 kB Flash and Single-Cycle MCU