- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄384645 > M7085L-SM1-R (UNISONIC TECHNOLOGIES CO LTD) PFM STEP-DOWN DC-DC CONTROLLER PDF資料下載
參數(shù)資料
| 型號(hào)： | M7085L-SM1-R |
| 廠商： | UNISONIC TECHNOLOGIES CO LTD |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | PFM STEP-DOWN DC-DC CONTROLLER |
| 中文描述： | SWITCHING CONTROLLER, PDSO8 |
| 封裝： | LEAD FREE, MSOP-8 |
| 文件頁(yè)數(shù)： | 6/8頁(yè) |
| 文件大?。?/td> | 139K |
| 代理商： | M7085L-SM1-R |
M7085
CMOS IC
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
6 of 8
QW-R502-092,A
APPLICAT ION INFORMAT ION
Setting the output voltage
Select an output voltage between 1.24V and V
IN
by connecting FB to a resistive voltage-divider between V
OUT
and GND (see the Typical Operating Circuit). Choose R2 for a reasonable bias current in the resistive divider. A wide
range of resistor values is acceptable.
R1,R2 is given by:
V
OUT
= 1.240* ( R1 + R2 ) / R2
Setting over current protection threshold by the R
DS(ON)
of the P-Channel
The UTC
M7085
has a cycle-by-cycle current limit. Current limit is sensed across the V
DS
of the P-Channel or
across an additional sense resistor. When current limit is activated, the UTC
M7085
turns off the external P-Channel
for a period of 9
μ
s(typical). The current limit is adjusted by an external resistor, R
ADJ
.
The current limit circuit is composed of the I
SENSE
comparator and the one-shot pulse generator. The positive input
of the I
SENSE
comparator is the ADJ pin. An internal 5.5μA current sink creates a voltage across the external R
ADJ
resistor. This voltage is compared to the voltage across the P-Channel or sense resistor. The ADJ voltage can be
calculated as follows:
V
ADJ
= V
IN
(R
ADJ
* 3.0
μ
A)
Where 3.0
μ
A is the minimum I
CL(ADJ)
value.
The negative input of the I
SENSE
comparator is the I
SENSE
pin that should be connected to the drain of the external
P-Channel. The inductor current is determined by sensing the V
DS
. It can be calculated as follows.
V
ISENSE
= V
IN
(R
DS(ON)
* I
IND_PEAK
) = V
IN
V
DS
I
SENSE
COMP
5.5μA
ADJ
5
C
ADJ
R
ADJ
I
SENSE
V
DS
V
IN
FIGURE 1. Current Sensing by V
DS
1
The current limit is activated when the voltage at the ADJ pin exceeds the voltage at the I
SENSE
pin. The I
SENSE
comparator triggers the 9
μ
s one shot pulse generator forcing the driver to turn the P-Channel off. The driver turns
the P-Channel back on after 9
μ
s. If the current has not reduced below the set threshold, the cycle will repeat
continuously.
A filter capacitor, C
ADJ
, should be placed as shown in Figure 1. C
ADJ
filters unwanted noise so that the I
SENSE
comparator will not be accidentally triggered. A value of 100pF to 1nF is recommended in most applications. Higher
values can be used to create a soft-start function. The current limit comparator has approximately 100ns of blanking
time. This ensures that the P-Channel is fully on when the current is sensed. However, under extreme conditions
such as cold temperature, some P-Channels may not fully turn on within the blanking time. In this case, the current
limit threshold must be increased. If the current limit function is used, the on time must be greater than 100ns. Under
low duty cycle operation, the maximum operating frequency will be limited by this minimum on time.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| M7085L-SM1-T | PFM STEP-DOWN DC-DC CONTROLLER |
| M7085-SM1-R | PFM STEP-DOWN DC-DC CONTROLLER |
| M7085-SM1-T | PFM STEP-DOWN DC-DC CONTROLLER |
| M74LCX16240DTR2G | Low−Voltage CMOS 16−Bit Buffer With 5 V−Tolerant Inputs and Outputs (3−State, Inverting) |
| M74LCX16374DTR2G | Low−Voltage CMOS 16−Bit D−Type Flip−Flop With 5 V−Tolerant Inputs and Outputs (3−State, Non−Inverting) |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| M7085L-SM1-T | 制造商:UTC-IC 制造商全稱:UTC-IC 功能描述:PFM STEP-DOWN DC-DC CONTROLLER |
| M7085-SM1-R | 制造商:UTC-IC 制造商全稱:UTC-IC 功能描述:PFM STEP-DOWN DC-DC CONTROLLER |
| M7085-SM1-T | 制造商:UTC-IC 制造商全稱:UTC-IC 功能描述:PFM STEP-DOWN DC-DC CONTROLLER |
| M7089 | 制造商:HAMAMATSU 制造商全稱:Hamamatsu Corporation 功能描述:Multichannel measurement unit |
| M708A | 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:PCM REMOTE CONTROL TRANSMITTER |
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。