- 您现在的位置：买卖IC网 > PDF目录69535 > TSM108ID (STMICROELECTRONICS) SWITCHING CONTROLLER, 130 kHz SWITCHING FREQ-MAX, PDSO14 PDF资料下载
参数资料
| 型号： | TSM108ID |
| 厂商： | STMICROELECTRONICS |
| 元件分类： | 稳压器 |
| 英文描述： | SWITCHING CONTROLLER, 130 kHz SWITCHING FREQ-MAX, PDSO14 |
| 封装： | PLASTIC, MICRO, SOP-14 |
| 文件页数： | 2/13页 |
| 文件大小： | 387K |
| 代理商： | TSM108ID |
TSM108
10/13
Mosfet: Pchannel Mosfet: Rdson = 100m
,
Ciss = 1nF.
Driver: TSM108
PWM frequency: 100kHz
Free wheel diode: Vf = 0.7V
Shunt: Rsense = 330m
The efficiency (
η) of a regulator is defined as the
ratio of the charging power (Pout) to the total pow-
er from the supply (Pin).
Eq3:
η = Pout/Pin
The output power is:
Pout=Iout x Vout where Iout is the charging cur-
rent (Vsense/Rsense = 625mA at full load) and
Vout is the regulated voltage (Vref(1+R1/R2) =
6V).
Pout = 3.75W
The input power can be found by adding the out-
put power (Pout) to the total power loss in the cir-
cuit (Plosses) i.e.
Pin = Pout + Plosses
The power is lost partly on the chip and partly on
the external components which are mainly the di-
ode, the switch and the shunt. Plosses = Pchip +
Pswitch + Pdiode + Pshunt.
In Plosses, we neglect the losses in the inductor
(because the current through the inductor is
smoothened making the serial resistor of the in-
ductor very low), and the losses in the Gate
(charge and discharge).
a. The power lost in the chip is Pchip = Vcc x Icc.
(Vcc = 12V, Icc = 6mA) Pchip = 72m
b. The power lost in the switch depends on the ON
resistance of the switch and the current passing
through it. Also there is power loss in the switch
during switching time (commutation losses) and
that depends on the switching frequency and the
rise and fall time of the switching signal.
Rise time (Pchannel goes off) depends on the out-
put source current of the TSM108 and the input
gate capacitance of the Mosfet.
Trise = Ciss x Vgate / Isource
Fall time (Pchannel goes on) depends on the out-
put sink current of the TSM108 and the input gate
capacitance of the Mosfet .
Tfall = Ciss x Vgate / Isink
Trise = 150ns and Tfall = 300ns (Vgate is approx
12V).
Pswitch = Prise + Pfall + Pon
where:
Prise = Iout x (Vcc+Vf) x Trise x PWMfreq / 2
Prise = 625mA x 12.7 x 150ns x 100kHz / 2.
Prise = 59.5mW
where:
Pfall = Iout x (Vcc+Vf) x Tfall x PWMfreq / 2
Pfall = 625mA x 12.7 x 300ns x 100kHz / 2.
Pfall = 119.1mW
where:
Pon = Rdson x Iout x D (where D is the duty cycle
- at full charge, D can be approximated to 1)
Pon = 100m
x 625mA. Pon = 39.1mW
Pswitch = 217.7mW
c. The power lost in the fly back diode is Pdiode =
Vf x Iout(1-D) where D = Vout/Vcc = 6/12. D = 0.5
Pdiode=219mW
d. the power lost in the sense resistor (shunt resis-
tor) is Pshunt = Rsense x Iout
Pshunt = 129mW
Therefore,
Plosses = Pchip+Pswitch+Pdiode+Pshunt
= 72mW + 217.7mW + 219mW + 129mW
Plosses = 638mW
The yield (efficiency) is
Pout / Pin = 3.75 / (3.75 + 0.638) = 85.5%
η = 85.5%
The following table gives a tentative yield improve-
ment view following the choice of some external
components. Be aware that some of the following
choices have non negligeable cost effects on the
total application.
Improved yield - by changing the external components value one by one
Rsense
330m
220m
----
Iout
625mA
936mA
----
Vout (R1/R2)
6V
-
7.5V
-
Rdson
100m
-
140m
--
Ciss
0nF
-
0.85nF
-
PWM Freq
100kHz
-
50kHz
-
Free Wheel
0.7V
----
0.3V
Yield
85.5%
85.6%
88.9%
85.7%
87.3%
88.1%
Cost influence
-
=
<
>
>>
相关PDF资料 |
PDF描述 |
|---|---|
| TSM108IDT | SWITCHING CONTROLLER, 130 kHz SWITCHING FREQ-MAX, PDSO14 |
| TSM111CD | POWER SUPPLY SUPPORT CKT, PDSO20 |
| TSM1121CDT | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO14 |
| TSM1121ID | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO14 |
| TSM1121IDT | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO14 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| TSM108IDT | 功能描述:电流型 PWM 控制器 Voltage/Current Cont RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14 |
| TSM108IDTH | 制造商:STMicroelectronics 功能描述:VOLTAGE AND CURRENT STEPDOWN PWM CONTROLLER |
| TSM109 | 制造商:STMICROELECTRONICS 制造商全称:STMicroelectronics 功能描述:DUAL COMPARATOR AND VOLTAGE REFERENCE |
| TSM10-9.5-520-TR | 制造商:E-Switch Inc 功能描述:SWITCH TACTILE 制造商:E-Switch Inc 功能描述:TSM Series |
| TSM109_04 | 制造商:STMICROELECTRONICS 制造商全称:STMicroelectronics 功能描述:Dual Comparator and Voltage Reference |
发布紧急采购，3分钟左右您将得到回复。