- 您现在的位置：买卖IC网 > Sheet目录17338 > ISL8201MEVAL1Z (Intersil)BOARD EVAL STEP-DOWN POL ISL8201
ISL8201M
Applications Information
The typical ISL8201M application schematic for input voltage
+5V or +12V is shown in Figure 11. External component
selection is primarily determined by the maximum load
current and input/output voltage.
Programming the Output Voltage
The ISL8201M has an internal 0.6V ±1.5% reference
voltage. Programming the output voltage requires a dividing
resistor (R FB ). The output voltage can be calculated as
shown in Equation 1:
If the COMP/EN pin is held low during power-up, the
initialization will be delayed until the COMP/EN is released
and its voltage rises above the V ENDIS trip point.
Figure 14 and Figure 15 show a typical power-up sequence
in more detail. The initialization starts at T 0 , when either
P VCC rises above V PORR , or the COMP/EN pin is released
(after POR). The COMP/EN will be pulled up by an internal
20μA current source, however, the timing will not begin until
the COMP/EN exceeds the V ENDIS trip point (at T 1 ). The
external capacitance of the disabling device, as well as the
compensation capacitors, will determine how quickly the
V OUT = 0.6 × ? 1 + --------------- ?
? R ?
9.76k
FB
(EQ. 1)
20μA current source will charge the COMP/EN pin. With
typical values, it should add a small delay compared to the
Note: ISL8201M has integrated 9.76k Ω resistance into the
module (dividing resistor for top side). The resistance
corresponding to different output voltages is as shown in
Table 1:
TABLE 1. RESISTANCE TO OUTPUT VOLTAGES
soft-start times. The COMP/EN will continue to ramp to ~1V.
From T 1 , there is a nominal 6.8ms delay, which allows the
PVCC pin to exceed 6.5V (if rising up towards 12V), so that
the internal bias regulator can turn on cleanly. At the same
time, the ISET pin is initialized by disabling the low-side gate
V OUT
R FB
V OUT
R FB
0.6V
open
1.8V
4.87k
1.05V
13k
2.5V
3.09k
1.2V
9.76k
3.3V
2.16k
1.5V
6.49k
5V
1.33k
driver and drawing I SET (nominal 21.5μA) through R SETI .
This sets up a voltage that will represent the I SET trip point.
At T 2 , there is a variable time period for the OCP sample and
hold operation (0.0ms to 3.4ms nominal; the longer time
occurs with the higher overcurrent setting). The sample and
hold uses a digital counter and DAC to save the voltage, so
the stored value does not degrade, as long as the P VCC is
Initialization (POR and OCP Sampling)
Figure 13 shows a start-up waveform of ISL8201M. The
power-on-reset (POR) function continually monitors the bias
voltage at the PVCC pin. Once the rising POR threshold has
exceeded 4V (V PORR nominal), the POR function initiates
the overcurrent protection (OCP) sample and hold operation
(while COMP/EN is ~1V). When the sampling is complete,
V OUT begins the soft-start ramp.
above V PORR (See “Overcurrent Protection (OCP)” on
page 10 for more details on the equations and variables).
Upon the completion of sample and hold at T 3 , the soft-start
operation is initiated, and the output voltage ramps up
between T 4 and T 5 .
COMP/EN
T 0
T 1
ISET
VOUT
FIGURE 14. I SET AND SOFT-START OPERATION
FIGURE 13. POR AND SOFT-START OPERATION
8
FN6657.2
October 21, 2010
发布紧急采购，3分钟左右您将得到回复。
相关PDF资料
EEC15DREI-S13
CONN EDGECARD 30POS .100 EXTEND
RCM15DCSH-S288
CONN EDGECARD 30POS .156 EXTEND
EEC20DREH-S13
CONN EDGECARD 40POS .100 EXTEND
RCC07DRXI
CONN EDGECARD 14POS DIP .100 SLD
594D106X9020B8T
CAP TANT 10UF 20V 10% 1611
TARS226M010
CAP TANT 22UF 10V 20% AXIAL
EBC15DCMI
CONN EDGECARD 30POS .100 WW
A9BAG-1606F
FLEX CABLE - AFF16G/AF16/AFE16T
相关代理商/技术参数
ISL8201MIRZ
功能描述:DC/DC转换器 STAND ALONE 10A DC/D CSTEPDWNPWRSUPPYMOD1
RoHS:否 制造商:Murata 产品: 输出功率: 输入电压范围:3.6 V to 5.5 V 输入电压（标称）: 输出端数量:1 输出电压（通道 1）:3.3 V 输出电流（通道 1）:600 mA 输出电压（通道 2）: 输出电流（通道 2）: 安装风格:SMD/SMT 封装 / 箱体尺寸:
ISL8201MIRZ-T
功能描述:DC/DC转换器 ST& ALONE 10A DC/DC DWN PWR SUPPLY MOD RoHS:否 制造商:Murata 产品: 输出功率: 输入电压范围:3.6 V to 5.5 V 输入电压（标称）: 输出端数量:1 输出电压（通道 1）:3.3 V 输出电流（通道 1）:600 mA 输出电压（通道 2）: 输出电流（通道 2）: 安装风格:SMD/SMT 封装 / 箱体尺寸:
ISL8204M
制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:Complete High Efficiency DC/DC Power Module
ISL8204MEVAL1Z
功能描述:电源管理IC开发工具 ISL8204 EVAL BRD 1 ROHS CMPL MOD
RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V
ISL8204MIRZ
功能描述:DC/DC转换器 STAND ALONE 4A DC/DC STEPDWNPWRSUPPYMOD15
RoHS:否 制造商:Murata 产品: 输出功率: 输入电压范围:3.6 V to 5.5 V 输入电压（标称）: 输出端数量:1 输出电压（通道 1）:3.3 V 输出电流（通道 1）:600 mA 输出电压（通道 2）: 输出电流（通道 2）: 安装风格:SMD/SMT 封装 / 箱体尺寸:
ISL8204MIRZ-T
功能描述:DC/DC转换器 ST& ALONE 4A DC/DC DWN PWR SUPPLY MOD RoHS:否 制造商:Murata 产品: 输出功率: 输入电压范围:3.6 V to 5.5 V 输入电压（标称）: 输出端数量:1 输出电压（通道 1）:3.3 V 输出电流（通道 1）:600 mA 输出电压（通道 2）: 输出电流（通道 2）: 安装风格:SMD/SMT 封装 / 箱体尺寸:
ISL8206M
制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:Complete High Efficiency DC/DC Power Module
ISL8206MEVAL1Z
功能描述:电源管理IC开发工具 ISL8206 EVAL BRD 1 ROHS CMPL MOD
RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V