- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄17103 > EVAL-AD5755-1SDZ (Analog Devices Inc)BOARD EVAL FOR AD5755-1 PDF資料下載
參數(shù)資料
| 型號： | EVAL-AD5755-1SDZ |
| 廠商： | Analog Devices Inc |
| 文件頁數(shù)： | 38/52頁 |
| 文件大小： | 0K |
| 描述： | BOARD EVAL FOR AD5755-1 |
| 視頻文件： | AD5755: 16-Bit Multi-Channel, Voltage and Current Output DAC |
| 標準包裝： | 1 |
| DAC 的數(shù)量： | 4 |
| 位數(shù)： | 16 |
| 數(shù)據(jù)接口： | 串行 |
| 設(shè)置時間： | 11µs |
| DAC 型： | 電流/電壓 |
| 工作溫度： | -40°C ~ 105°C |
| 已供物品： | 板 |
| 已用 IC / 零件： | * |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁第37頁當前第38頁第39頁第40頁第41頁第42頁第43頁第44頁第45頁第46頁第47頁第48頁第49頁第50頁第51頁第52頁
Data Sheet
AD5755-1
Rev. E | Page 43 of 52
POWER DISSIPATION CONTROL
The AD5755-1 contains integrated dynamic power control
using a dc-to-dc boost converter circuit, allowing reductions in
power consumption from standard designs when using the part
in current output mode.
In standard current input module designs, the load resistor
values can range from typically 50 to 750 . Output module
systems must source enough voltage to meet the compliance
voltage requirement across the full range of load resistor values.
For example, in a 4 mA to 20 mA loop when driving 20 mA, a
compliance voltage of >15 V is required. When driving 20 mA
into a 50 load, only 1 V compliance is required.
The AD5755-1 circuitry senses the output voltage and regulates
this voltage to meet compliance requirements plus a small
headroom voltage. The AD5755-1 is capable of driving up to
24 mA through a 1 k load.
DC-TO-DC CONVERTERS
The AD5755-1 contains four independent dc-to-dc converters.
These are used to provide dynamic control of the VBOOST supply
voltage for each channel (see Figure 73). Figure 80 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
09226-
077
Figure 80. DC-to-DC Circuit
Table 34. Recommended DC-to-DC Components
Symbol
Component
Value
Manufacturer
L
DCDC
XAL4040-103
10 H
Coilcraft
C
DCDC
GRM32ER71H475KA88L
4.7 F
Murata
D
DCDC
PMEG3010BEA
0.38 V
F
NXP
It is recommended to place a 10 , 100 nF low-pass RC filter
after CDCDC. This 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 AD5755-1 output channel. These are
designed to operate in discontinuous conduction mode (DCM)
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 53 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 so that the outputs of the IOUT_x and VOUT_x stages
can be tied together.
DC-to-DC Converter Settling Time
When 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%). A typical plot of the output settling time can be
found in Figure 49. 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 25). On reaching
this maximum voltage, 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 has decayed 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 81.
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
VO
LT
A
G
E
(V)
TIME (ms)
VMAX
0mA TO 24mA RANGE, 24mA OUTPUT
OUTPUT UNLOADED
DC-DCMaxV = 11 (29.5V)
DC_DC BIT
09226-
183
DCDCx BIT = 0
DCDCx BIT = 1
f
SW = 410kHz
TA = 25°C
Figure 81. Operation on Reaching VMAX
As can be seen in Figure 81, the DC-DCx bit in the status register
asserts when the AD5755-1 is ramping to the VMAX value but
deasserts when the voltage is decaying to VMAX ~0.4 V.
DC-to-DC Converter On-Board Switch
The AD5755-1 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 AD5755-1 dc-to-dc converter switching frequency can be
selected from the dc-to-dc control register. The phasing of the
channels can also be adjusted so that the dc-to-dc converter can
clock on different edges (see Table 25). For typical applications,
a 410 kHz frequency is recommended. At light loads (low output
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| R-7215D | CONV DC/DC 2A 19-28VIN 15V |
| VE-J14-EZ | CONVERTER MOD DC/DC 48V 25W |
| R-7212P | CONV DC/DC 2A 15-28VIN 12V |
| R-7212D | CONV DC/DC 2A 15-28VIN 12V |
| VI-JVX-EZ | CONVERTER MOD DC/DC 5.2V 25W |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| EVAL-AD5755SDZ | 功能描述:BOARD EVAL FOR AD5755 RoHS:是 類別:編程器，開發(fā)系統(tǒng) >> 評估板 - 數(shù)模轉(zhuǎn)換器 (DAC) 系列:- 產(chǎn)品培訓模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標準包裝:1 系列:- DAC 的數(shù)量:4 位數(shù):12 采樣率（每秒）:- 數(shù)據(jù)接口:串行，SPI? 設(shè)置時間:3µs DAC 型:電流/電壓 工作溫度:-40°C ~ 85°C 已供物品:板 已用 IC / 零件:MAX5581 |
| EVAL-AD5757SDZ | 功能描述:BOARD EVAL FOR AD5757 RoHS:是 類別:編程器，開發(fā)系統(tǒng) >> 評估板 - 數(shù)模轉(zhuǎn)換器 (DAC) 系列:- 產(chǎn)品培訓模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標準包裝:1 系列:- DAC 的數(shù)量:4 位數(shù):12 采樣率（每秒）:- 數(shù)據(jù)接口:串行，SPI? 設(shè)置時間:3µs DAC 型:電流/電壓 工作溫度:-40°C ~ 85°C 已供物品:板 已用 IC / 零件:MAX5581 |
| EVAL-AD5760SDZ | 功能描述:BOARD EVAL FOR AD5760SDZ RoHS:否 類別:編程器，開發(fā)系統(tǒng) >> 評估板 - 數(shù)模轉(zhuǎn)換器 (DAC) 系列:* 產(chǎn)品培訓模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標準包裝:1 系列:- DAC 的數(shù)量:4 位數(shù):12 采樣率（每秒）:- 數(shù)據(jù)接口:串行，SPI? 設(shè)置時間:3µs DAC 型:電流/電壓 工作溫度:-40°C ~ 85°C 已供物品:板 已用 IC / 零件:MAX5581 |
| EVAL-AD5764EB | 制造商:Analog Devices 功能描述:EVALUATION BOARD FOR QUAD, 16-BIT, HIGH ACCURACY, SERIAL INPUT, BIPOLAR VOLTAGE OUTPUT DAC 制造商:Analog Devices 功能描述:EVALUATION CONTROL BOARD I.C. - Bulk |
| EVAL-AD5764EBZ | 功能描述:BOARD EVAL FOR AD5764 RoHS:是 類別:編程器，開發(fā)系統(tǒng) >> 評估板 - 數(shù)模轉(zhuǎn)換器 (DAC) 系列:- 產(chǎn)品培訓模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標準包裝:1 系列:- DAC 的數(shù)量:4 位數(shù):12 采樣率（每秒）:- 數(shù)據(jù)接口:串行，SPI? 設(shè)置時間:3µs DAC 型:電流/電壓 工作溫度:-40°C ~ 85°C 已供物品:板 已用 IC / 零件:MAX5581 |
發(fā)布緊急采購，3分鐘左右您將得到回復。