These are use" />
參數(shù)資料
型號(hào)： AD5735ACPZ-REEL7
廠商： Analog Devices Inc
文件頁(yè)數(shù)： 37/48頁(yè)
文件大小： 0K
描述： IC DAC QUAD VOLT CUR 64LFCSP
標(biāo)準(zhǔn)包裝： 750
設(shè)置時(shí)間： 18µs
位數(shù)： 12
數(shù)據(jù)接口： DSP，MICROWIRE?，QSPI?，串行，SPI?
轉(zhuǎn)換器數(shù)目： 4
電壓電源： 模擬和數(shù)字，雙 ±
工作溫度： -40°C ~ 105°C
安裝類型： 表面貼裝
封裝/外殼： 64-VFQFN 裸露焊盤(pán)，CSP
供應(yīng)商設(shè)備封裝： 64-LFCSP-VQ（9x9）
包裝： 帶卷 (TR)
輸出數(shù)目和類型： 4 電流，4 電壓
采樣率（每秒）： *
AD5735
Data Sheet
Rev. C | Page 42 of 48
DC-TO-DC CONVERTERS
The AD5735 contains four independent dc-to-dc converters.
These are used to provide dynamic control of the VBOOST_x supply
voltage for each channel (see Figure 71). Figure 77 shows the
discrete components needed for the dc-to-dc circuitry, and the
following sections describe component selection and operation
of this circuitry.
AVCC
LDCDC
DDCDC
CDCDC
4.7F
CFILTER
0.1F
RFILTER
CIN
SWx
VBOOST_x
≥10F
10
10H
09961-
077
Figure 77. DC-to-DC Circuit
Table 36. Recommended Components for a DC-to-DC Converter
Symbol
Component
Value
Manufacturer
L
DCDC
XAL4040-103
10 H
Coilcraft
C
DCDC
GRM32ER71H475KA88L
4.7 F
Murata
D
DCDC
PMEG3010BEA
0.285 V
F
NXP
It is recommended that a 10 , 100 nF low-pass RC filter be
placed after CDCDC. This filter consumes a small amount of power
but reduces the amount of ripple on the VBOOST_x supply.
DC-to-DC Converter Operation
The on-board dc-to-dc converters use a constant frequency, peak
current mode control scheme to step up an AVCC input of 4.5 V
to 5.5 V to drive the AD5735 output channel. These converters
are designed to operate in discontinuous conduction mode with
a duty cycle of <90% typical. Discontinuous conduction mode
refers to a mode of operation where the inductor current goes
to zero for an appreciable percentage of the switching cycle. The
dc-to-dc converters are nonsynchronous; that is, they require an
external Schottky diode.
DC-to-DC Converter Output Voltage
When a channel current output is enabled, the converter regulates
the VBOOST_x supply to 7.4 V (±5%) or (IOUT × RLOAD + Headroom),
whichever is greater (see Figure 51 for a plot of headroom
supplied vs. output current). In voltage output mode with the
output disabled, the converter regulates the VBOOST_x supply to
15 V (±5%). In current output mode with the output disabled,
the converter regulates the VBOOST_x supply to 7.4 V (±5%).
Within a channel, the VOUT_x and IOUT_x stages share a common
VBOOST_x supply; therefore, the outputs of the IOUT_x and VOUT_x
stages can be tied together (see the Voltage and Current Output
DC-to-DC Converter Settling Time
In current output mode, the settling time for a step greater than
~1 V (IOUT × RLOAD) is dominated by the settling time of the dc-to-
dc converter. The exception to this is when the required voltage at
the IOUT_x pin plus the compliance voltage is below 7.4 V (±5%).
Figure 47 shows a typical plot of the output settling time. This
plot is for a 1 k load. The settling time for smaller loads is faster.
The settling time for current steps less than 24 mA is also faster.
DC-to-DC Converter VMAX Functionality
The maximum VBOOST_x voltage is set in the dc-to-dc control
register (23 V, 24.5 V, 27 V, or 29.5 V; see Table 28). When the
maximum voltage is reached, the dc-to-dc converter is disabled,
and the VBOOST_x voltage is allowed to decay by ~0.4 V. After the
VBOOST_x voltage decays by ~0.4 V, the dc-to-dc converter is
reenabled, and the voltage ramps up again to VMAX, if still
required. This operation is shown in Figure 78.
28.6
28.7
28.8
28.9
29.0
29.1
29.2
29.3
29.4
29.5
29.6
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
V
B
OOS
T
_
x
VO
LT
A
G
E
(V)
TIME (ms)
VMAX
0mA TO 24mA RANGE, 24mA OUTPUT
OUTPUT UNLOADED
DC-DC MaxV BITS = 29.5V
DC-DCx BIT
DC-DCx BIT = 0
DC-DCx BIT = 1
f
SW = 410kHz
TA = 25°C
09961-
183
Figure 78. Operation on Reaching VMAX
As shown in Figure 78, the DC-DCx bit in the status register
is asserted when the AD5735 ramps up to the VMAX value but
is deasserted when the voltage decays to VMAX ~0.4 V.
DC-to-DC Converter On-Board Switch
The AD5735 contains a 0.425 internal switch. The switch
current is monitored on a pulse-by-pulse basis and is limited
to 0.8 A peak current.
DC-to-DC Converter Switching Frequency and Phase
The AD5735 dc-to-dc converter switching frequency can be
selected from the dc-to-dc control register (see Table 28). The
phasing of the channels can also be adjusted so that the dc-to-dc
converters can clock on different edges. For typical applications,
a 410 kHz frequency is recommended. At light loads (low output
current and small load resistor), the dc-to-dc converter enters a
pulse-skipping mode to minimize switching power dissipation.
DC-to-DC Converter Inductor Selection
For typical 4 mA to 20 mA applications, a 10 H inductor (such
as the XAL4040-103 from Coilcraft), combined with a switching
frequency of 410 kHz, allows up to 24 mA to be driven into a
load resistance of up to 1 k with an AVCC supply of 4.5 V to
5.5 V. It is important to ensure that the inductor can handle the
peak current without saturating, especially at the maximum
ambient temperature. If the inductor enters saturation mode,
efficiency decreases. The inductance value also drops during
saturation and may result in the dc-to-dc converter circuit not
being able to supply the required output power.
相關(guān)PDF資料
PDF描述
AD5737ACPZ IC DAC QUAD 12BIT CUR 64-LFCSP
AD573JD IC ADC 10BIT SAR REG 20-CDIP
AD5744RCSUZ-REEL7 IC DAC QUAD 14BIT 1LSB 32TQFP
AD574AKPZ-REEL IC ADC 12BIT W/REF/CLK 28-PLCC
AD5752AREZ IC DAC DUAL 16BIT SERIAL 24TSSOP
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AD5737 制造商:AD 制造商全稱:Analog Devices 功能描述:Quad Channel, 16-Bit, Serial Input, 4-20mA Output DAC, Dynamic Power Control, HART Connectivity
AD5737_12 制造商:AD 制造商全稱:Analog Devices 功能描述:Quad-Channel, 12-Bit, Serial Input, 4 mA to 20 mA Output
AD5737ACPZ 功能描述:IC DAC QUAD 12BIT CUR 64-LFCSP 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:1 系列:- 設(shè)置時(shí)間:4.5µs 位數(shù):12 數(shù)據(jù)接口:串行，SPI? 轉(zhuǎn)換器數(shù)目:1 電壓電源:單電源 功率耗散（最大）:- 工作溫度:-40°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:8-SOIC（0.154"，3.90mm 寬） 供應(yīng)商設(shè)備封裝:8-SOICN 包裝:剪切帶 (CT) 輸出數(shù)目和類型:1 電壓，單極；1 電壓，雙極 采樣率（每秒）:* 其它名稱:MCP4921T-E/SNCTMCP4921T-E/SNRCTMCP4921T-E/SNRCT-ND
AD5737ACPZ-RL7 制造商:AD 制造商全稱:Analog Devices 功能描述:Quad-Channel, 12-Bit, Serial Input, 4 mA to 20 mA Output
AD5737X 制造商:AD 制造商全稱:Analog Devices 功能描述:Quad Channel, 16-Bit, Serial Input, 4-20mA Output DAC, Dynamic Power Control, HART Connectivity
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫(xiě)一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*