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参数资料
| 型号： | ADM1069ASTZ |
| 厂商： | Analog Devices Inc |
| 文件页数： | 21/32页 |
| 文件大小： | 0K |
| 描述： | IC SUPERVISOR/SEQUENCER 32-LQFP |
| 标准包装： | 1 |
| 系列： | Super Sequencer® |
| 类型： | 序列发生器 |
| 监视电压数目： | 8 |
| 输出： | 可编程 |
| 电压 - 阀值： | 8 种可选阀值组合 |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 32-LQFP |
| 供应商设备封装： | 32-LQFP（7x7） |
| 包装： | 托盘 |
| 产品目录页面： | 788 (CN2011-ZH PDF) |
| 配用： | EVAL-ADM1069LQEBZ-ND - BOARD EVALUATION FOR ADM1069LQ |
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ADM1069
SUPPLY MARGINING
OVERVIEW
It is often necessary for the system designer to adjust supplies,
either to optimize their level or force them away from nominal
values to characterize the system performance under these
conditions. This is a function typically performed during an
in-circuit test (ICT), such as when a manufacturer wants to
guarantee that a product under test functions correctly at
nominal supplies minus 10%.
OPEN-LOOP SUPPLY MARGINING
The simplest method of margining a supply is to implement
an open-loop technique (see Figure 32). A popular way to do
this is to switch extra resistors into the feedback node of a power
module, such as a dc-to-dc converter or low dropout regulator
(LDO). The extra resistor alters the voltage at the feedback or
trim node and forces the output voltage to margin up or down
by a certain amount.
The ADM1069 can perform open-loop margining for up to four
supplies. The four on-board voltage DACs (DAC1 to DAC4) can
drive into the feedback pins of the power modules to be margined.
The simplest circuit to implement this function is an attenuation
resistor that connects the DACx pin to the feedback node of a
dc-to-dc converter. When the DACx output voltage is set equal
to the feedback voltage, no current flows into the attenuation
resistor, and the dc-to-dc converter output voltage does not change.
Taking DACx above the feedback voltage forces current into the
feedback node, and the output of the dc-to-dc converter is forced
to fall to compensate for this. The dc-to-dc converter output can be
forced high by setting the DACx output voltage lower than the
feedback node voltage. The series resistor can be split in two, and
the node between them can be decoupled with a capacitor to
ground. This can help to decouple any noise picked up from the
board. Decoupling to a ground local to the dc-to-dc converter
is recommended.
The ADM1069 can be commanded to margin a supply up or
down over the SMBus by updating the values on the relevant
DAC output.
VIN
V OUT
CLOSED-LOOP SUPPLY MARGINING
A more accurate and comprehensive method of margining is to
implement a closed-loop system (see Figure 33). The voltage on
the rail to be margined can be read back to accurately margin the
rail to the target voltage. The ADM1069 incorporates all the circuits
required to do this, with the 12-bit successive approximation ADC
used to read back the level of the supervised voltages, and the
six voltage output DACs, implemented as described in the Open-
These circuits can be used along with other intelligence, such as
a microcontroller, to implement a closed-loop margining system
that allows any dc-to-dc converter or LDO supply to be set to
any voltage, accurate to within ±0.5% of the target.
To implement closed-loop margining,
1. Disable the four DACx outputs.
2. Set the DAC output voltage equal to the voltage on the
feedback node.
3. Enable the DAC.
4. Read the voltage at the dc-to-dc converter output that
is connected to one of the VPx, VH, or VXx pins.
5. If necessary, modify the DACx output code up or down
to adjust the dc-to-dc converter output voltage. Otherwise,
stop because the target voltage has been reached.
6. Set the DAC output voltage to a value that alters the supply
output by the required amount (for example, ±5%).
7. Repeat Step 4 through Step 6 until the measured supply
reaches the target voltage.
Step 1 to Step 3 ensure that when the DACx output buffer is
turned on, it has little effect on the dc-to-dc converter output.
The DAC output buffer is designed to power up without
glitching by first powering up the buffer to follow the pin
voltage. It does not drive out onto the pin at this time. Once the
output buffer is properly enabled, the buffer input is switched
over to the DAC, and the output stage of the buffer is turned on.
Output glitching is negligible.
MICROCONTROLLER
ADM1069
OUTPUT
DC-TO-DC
CONVERTER
FEEDBACK
R1
ATTENUATION
RESISTOR, R3
DACx
DAC
DEVICE
CONTROLLER
(SMBus)
GND
R2
PCB
TRACE NOISE
DECOUPLING
CAPACITOR
Figure 32. Open-Loop Margining System Using the ADM1069
Rev. C | Page 21 of 32
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| ADM1069ASTZ-REEL | 功能描述:IC SEQUENCER/SUPERVISOR 32LQFP RoHS:是 类别:集成电路 (IC) >> PMIC - 监控器 系列:Super Sequencer® 标准包装:1 系列:- 类型:简单复位/加电复位 监视电压数目:1 输出:开路漏极或开路集电极 复位:高有效 复位超时:- 电压 - 阀值:1.8V 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:6-TSOP（0.059"，1.50mm 宽）5 引线 供应商设备封装:5-TSOP 包装:剪切带 (CT) 其它名称:NCP301HSN18T1GOSCT |
| ADM1069ASTZ-REEL7 | 功能描述:IC SEQUENCER/SUPERVISOR 32LQFP RoHS:是 类别:集成电路 (IC) >> PMIC - 监控器 系列:Super Sequencer® 其它有关文件:STM6905 View All Specifications 标准包装:1 系列:- 类型:多压监控器 监视电压数目:5 输出:开路漏极或开路集电极 复位:低有效 复位超时:最小为 140 ms 电压 - 阀值:2.188V，2.955V，可调，可调，可调 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:8-TSSOP，8-MSOP（0.118"，3.00mm 宽） 供应商设备封装:8-TSSOP 包装:Digi-Reel® 产品目录页面:1197 (CN2011-ZH PDF) 其它名称:497-8728-6 |
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| ADM1070ART-REEL | 制造商:Analog Devices 功能描述:Hot Swap Controller 1-CH -80V 6-Pin SOT-23 T/R 制造商:Analog Devices 功能描述:6-PIN -48V HOT SWAP CONTROLLER I.C. - Tape and Reel 制造商:Rochester Electronics LLC 功能描述:6-PIN -48V HOT SWAP CONTROLLER I.C. - Tape and Reel |
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