参数资料
| 型号： | SI9105DN02-E3 |
| 厂商： | Vishay Siliconix |
| 文件页数： | 6/11页 |
| 文件大小： | 0K |
| 描述： | IC REG FLYBK ISOLATED 4V 20PLCC |
| 标准包装： | 500 |
| 类型： | 回扫，隔离 |
| 输出类型： | 固定 |
| 输出数： | 1 |
| 输出电压： | 4V |
| 输入电压： | 10 V ~ 120 V |
| PWM 型： | 电流模式 |
| 频率 - 开关： | 40kHz ~ 1MHz |
| 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： | 20-LCC（J 形引线） |
| 包装： | 带卷 (TR) |
| 供应商设备封装： | 20-PLCC（9x9） |
Si9105
Vishay Siliconix
DETAILED DESCRIPTION
Pre-Regulator/Start-Up Section
Product is End of Life 3/2014
Due to the low quiescent current requirement of the Si9105
control circuitry, bias power can be supplied from the unreg-
ulated input power source, from an external regulated low-
voltage supply, or from an auxiliary "bootstrap" winding on
the output inductor or transformer.
When power is first applied during start-up, + V IN will draw a
constant current. The magnitude of this current is determined
by a high-voltage depletion MOSFET device which is con-
nected between + V IN and V CC . This start-up circuitry pro-
vides initial power to the IC by charging an external bypass
capacitance connected to the V CC pin. The constant current
is disabled when V CC exceeds 9.3 V. If V CC is not forced to
The output of the reference section is connected internally to
the non-inverting input of the error amplifier. Nominal refer-
ence output voltage is 4 V. The trimming procedure that is
used on the Si9105 brings the output of the error amplifier
(which is configured for unity gain during trimming) to within
± 1 % of 4 V. This automatically compensates for the input
offset voltage in the error amplifier.
The output impedance of the reference section has been
purposely made high so that a low impedance external volt-
age source can be used to override the internal voltage
source, if desired, without otherwise altering the perfor-
mance of the device.
exceed the 9.3 V threshold, then V CC will be regulated to a
nominal value of 9.3 V by the pre-regulator circuit.
Error Amplifier
As the supply voltage rises toward the normal operating con-
ditions, an internal undervoltage (UV) lockout circuit keeps
the output MOSFET disabled until V CC exceeds the under-
voltage lockout threshold (typically 8.7 V). This guarantees
that the control logic will be functioning properly and that suf-
ficient gate drive voltage is available before the MOSFET
turns on. The design of the IC is such that the undervoltage
lockout threshold will not exceed the pre-regulator turn-off
voltage. Power dissipation can be minimized by providing an
external power source to V CC such that the constant current
Closed-loop regulation is provided by the error amplifier,
whose 1 k Ω dynamic output impedance enables it to be used
with feedback compensation (unlike transconductance
amplifiers). A MOS differential input stage provides for low
input current. The noninverting input to the error amplifier
(V REF ) is internally connected to the output of the reference
supply and should be bypassed with a small capacitor to
ground.
source is always disabled.
Oscillator Section
BIAS
The oscillator consists of a ring of CMOS inverters, capaci-
To properly set the bias for the Si9105, a 820 k Ω resistor
should be tied from BIAS to - V IN . This determines the mag-
nitude of bias current in all of the analog sections and the
pull-up current for the SHUTDOWN and RESET pins. The
current flowing in the bias resistor is nominally 7.5 μA.
Reference Section
The reference section of the Si9105 consists of a tempera-
ture compensated buried zener and trimmable divider net-
work.
www.vishay.com
6
tors, and a capacitor discharge switch. Frequency is set by
an external resistor between the OSC IN and OSC OUT pins.
(See Typical Characteristics graph of resistor value vs. fre-
quency.) The DISCHARGE pin should be tied to - V IN for nor-
mal internal oscillator operation. A frequency divider in the
logic section limits switch duty cycle to a maximum of 50 %
by locking the switching frequency to one half of the oscillator
frequency.
Remote synchronization can be accomplished by capacitive
coupling of a synchronization pulse into the OSC IN terminal.
For a 5 V pulse amplitude and 0.5 μs pulse width, typical val-
ues would be 100 pF in series with 3 k Ω to OSC IN.
Document Number: 70003
S-70497-Rev. I, 19-Mar-07
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相关代理商/技术参数 |
参数描述 |
|---|---|
| SI9105DN02-T1 | 制造商:VISHAY 制造商全称:Vishay Siliconix 功能描述:1-W High-Voltage Switchmode Regulator |
| SI9105DN02-T1-E3 | 功能描述:开关变换器、稳压器与控制器 1W High-Voltage Switchmode RoHS:否 制造商:Texas Instruments 输出电压:1.2 V to 10 V 输出电流:300 mA 输出功率: 输入电压:3 V to 17 V 开关频率:1 MHz 工作温度范围: 安装风格:SMD/SMT 封装 / 箱体:WSON-8 封装:Reel |
| SI9105DW | 功能描述:开关变换器、稳压器与控制器 1W HV Switchmode Reg RoHS:否 制造商:Texas Instruments 输出电压:1.2 V to 10 V 输出电流:300 mA 输出功率: 输入电压:3 V to 17 V 开关频率:1 MHz 工作温度范围: 安装风格:SMD/SMT 封装 / 箱体:WSON-8 封装:Reel |
| SI9105DW-E3 | 功能描述:开关变换器、稳压器与控制器 1W High-Voltage Switchmode RoHS:否 制造商:Texas Instruments 输出电压:1.2 V to 10 V 输出电流:300 mA 输出功率: 输入电压:3 V to 17 V 开关频率:1 MHz 工作温度范围: 安装风格:SMD/SMT 封装 / 箱体:WSON-8 封装:Reel |
| SI9105DW-T1 | 功能描述:开关变换器、稳压器与控制器 1W High-Voltage Switchmode RoHS:否 制造商:Texas Instruments 输出电压:1.2 V to 10 V 输出电流:300 mA 输出功率: 输入电压:3 V to 17 V 开关频率:1 MHz 工作温度范围: 安装风格:SMD/SMT 封装 / 箱体:WSON-8 封装:Reel |
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