参数资料
| 型号： | ADP1611ARMZ-R7 |
| 厂商： | Analog Devices Inc |
| 文件页数： | 10/20页 |
| 文件大小： | 0K |
| 描述： | IC REG BOOST ADJ 1.2A 8MSOP |
| 标准包装： | 1 |
| 类型： | 升压（升压） |
| 输出类型： | 可调式 |
| 输出数： | 1 |
| 输出电压： | 可调至 20V |
| 输入电压： | 2.5 V ~ 5.5 V |
| PWM 型： | 电流模式 |
| 频率 - 开关： | 700kHz，1.23MHz |
| 电流 - 输出： | 1.2A |
| 同步整流器： | 无 |
| 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） |
| 包装： | 标准包装 |
| 供应商设备封装： | 8-MSOP |
| 其它名称： | ADP1611ARMZ-R7DKR |
ADP1611
THEORY OF OPERATION
The ADP1611 current-mode step-up switching converter
converts a 2.5 V to 5.5 V input voltage up to an output voltage
as high as 20 V. The 1.2 A internal switch allows a high output
current, and the high 1.2 MHz switching frequency allows tiny
external components. The switch current is monitored on a
pulse-by-pulse basis to limit it to 2 A.
CURRENT-MODE PWM OPERATION
The ADP1611 uses current-mode architecture to regulate the
output voltage. The output voltage is monitored at FB through a
resistive voltage divider. The voltage at FB is compared to the
internal 1.23 V reference by the internal transconductance error
amplifier to create an error current at COMP. A series resistor-
capacitor at COMP converts the error current to a voltage.
The switch current is internally measured and added to the
stabilizing ramp, and the resulting sum is compared to the error
voltage at COMP to control the PWM modulator. This current-
mode regulation system allows fast transient response, while
maintaining a stable output voltage. By selecting the proper
resistor-capacitor network from COMP to GND, the regulator
response is optimized for a wide range of input voltages, output
ON/OFF CONTROL
The SD input turns the ADP1611 regulator on or off. Drive SD
low to turn off the regulator and reduce the input current to
10 nA. Drive SD high to turn on the regulator.
When the step-up dc-to-dc switching converter is turned off,
there is a dc path from the input to the output through the
inductor and output rectifier. This causes the output voltage to
remain slightly below the input voltage by the forward voltage
of the rectifier, preventing the output voltage from dropping to
0 when the regulator is shut down. Figure 28 shows the applica-
tion circuit to disconnect the output voltage from the input
voltage at shutdown.
SETTING THE OUTPUT VOLTAGE
The ADP1611 features an adjustable output voltage range of V IN
to 20 V. The output voltage is set by the resistive voltage divider
(R1 and R2 in Figure 2) from the output voltage (V OUT ) to the
1.230 V feedback input at FB. Use the following formula to
determine the output voltage:
voltages, and load conditions.
V OUT = 1.23 × (1 + R1 / R2 )
(1)
FREQUENCY SELECTION
The ADP1611 frequency is user-selectable and operates at
either 700 kHz to optimize the regulator for high efficiency
Use an R2 resistance of 10 k? or less to prevent output voltage
errors due to the 10 nA FB input bias current. Choose R1 based
on the following formula:
? V ? 1 . 23 ?
or at 1.2 MHz for small external components. Connect RT to
IN for 1.2 MHz operation, or connect RT to GND for 700 kHz
operation. To achieve the maximum duty cycle, which might
? 1 . 23 ?
R1 = R2 × ? OUT ?
(2)
be required for converting a low input voltage to a high output
voltage, use the lower 700 kHz switching frequency.
SOFT START
To prevent input inrush current at startup, connect a capacitor
from SS to GND to set the soft-start period. When the device is
in shutdown (SD is at GND) or the input voltage is below the
2.4 V undervoltage lockout voltage, SS is internally shorted to
GND to discharge the soft start capacitor. Once the ADP1611 is
turned on, SS sources 3 μA to the soft-start capacitor at startup.
As the soft-start capacitor charges, it limits the voltage at
COMP. Because of the current-mode regulator, the voltage at
COMP is proportional to the switch peak current, and,
therefore, the input current. By slowly charging the soft-start
capacitor, the input current ramps slowly to prevent it from
overshooting excessively at startup.
INDUCTOR SELECTION
The inductor is an essential part of the step-up switching
converter. It stores energy during the on time, and transfers that
energy to the output through the output rectifier during the off
time. Use inductance in the range of 1 μH to 22 μH. In general,
lower inductance values have higher saturation current and
lower series resistance for a given physical size. However, lower
inductance results in higher peak current that can lead to
reduced efficiency and greater input and/or output ripple and
noise. Peak-to-peak inductor ripple current at close to 30% of
the maximum dc input current typically yields an optimal
compromise.
For determining the inductor ripple current, the input (V IN ) and
output (V OUT ) voltages determine the switch duty cycle (D) by
the following equation:
Rev. 0 | Page 10 of 20
D =
V OUT ? V IN
V OUT
(3)
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相关代理商/技术参数 |
参数描述 |
|---|---|
| ADP1611-EVAL | 制造商:AD 制造商全称:Analog Devices 功能描述:20 V,1.2 MHz Step-Up DC-to-DC Switching Converter |
| ADP1612 | 制造商:AD 制造商全称:Analog Devices 功能描述:650 kHz /1.3 MHz Step-Up PWM DC-to-DC Switching Converters |
| ADP1612-5-EVALZ | 功能描述:BOARD EVAL ADP1612 5V VOUT RoHS:是 类别:编程器，开发系统 >> 评估板 - DC/DC 与 AC/DC（离线）SMPS 系列:- 标准包装:1 系列:- 主要目的:DC/DC，步降 输出及类型:1，非隔离 功率 - 输出:- 输出电压:3.3V 电流 - 输出:3A 输入电压:4.5 V ~ 28 V 稳压器拓扑结构:降压 频率 - 开关:250kHz 板类型:完全填充 已供物品:板 已用 IC / 零件:L7981 其它名称:497-12113STEVAL-ISA094V1-ND |
| ADP1612ARMZ-R7 | 功能描述:IC REG BST SEPIC ADJ 1.4A 8MSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 产品培训模块:High Efficiency Current Mode Switching Regulators CMOS LDO Regulators 特色产品:BD91x Series Step-Down Regulators 标准包装:2,500 系列:- 类型:降压（降压） 输出类型:两者兼有 输出数:2 输出电压:3.3V，0.8 V ~ 2.5 V 输入电压:4.5 V ~ 5.5 V PWM 型:电流模式 频率 - 开关:1MHz 电流 - 输出:1.5A 同步整流器:是 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:20-VFQFN 裸露焊盘 包装:带卷 (TR) 供应商设备封装:VQFN020V4040 产品目录页面:1373 (CN2011-ZH PDF) 其它名称:BD9152MUV-E2TR |
| ADP1612-BL1-EVZ | 制造商:Analog Devices 功能描述:BLANK ADISIMPOWER EVAL ADP1612 - Boxed Product (Development Kits) |
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