參數(shù)資料
型號: CS4124YN16
廠商: ZF Electronics Corporation
英文描述: CAT 7 PLENUM BLUE BULK CABLE
中文描述: 場效應管高邊PWM控制器
文件頁數(shù): 4/6頁
文件大?。?/td> 149K
代理商: CS4124YN16
C
1198
Application Information
Oscillator
The IC sets up a constant frequency triangle wave at the
C
OSC
lead whose frequency is related to the external com-
ponents R
OSC
and C
OSC
, by the following equation:
Frequency =
The peak and valley of the triangle wave are proportional
to V
CC
by the following:
V
VALLEY
= 0.1
×
V
CC
V
PEAK
= 0.7
×
V
CC
This is required to make the voltage compensation function
properly. In order to keep the frequency of the oscillator
constant the current that charges C
OSC
must also vary with
supply. R
OSC
sets up the current which charges C
OSC
. The
voltage across R
OSC
is 50% of V
CC
and therefore:
I
ROSC
= 0.5
×
I
ROSC
is multiplied by (2) internally and transferred to the
C
OSC
lead. Therefore:
I
COSC
= ±
The period of the oscillator is:
T = 2C
OSC
×
The R
OSC
and C
OSC
components can be varied to create fre-
quencies over the range of 15Hz to 25kHz. With the sug-
gested values of 93.1k
and 470pF for R
OSC
and C
OSC
, the
nominal frequency will be approximately 20 kHz. I
ROSC
, at
V
CC
= 14V, will be 66.7 μA. I
ROSC
should not change over a
more than 2:1 ratio and therefore C
OSC
should be changed
to adjust the oscillator frequency.
Voltage Duty Cycle Conversion
The IC translates an input voltage at the CTL lead into a
duty cycle at the OUTPUT lead. The transfer function
incorporates Cherry Semiconductor’s patented Voltage
Compensation method to keep the average voltage and
current across the load constant regardless of fluctuations
in the supply voltage. The duty cycle is varied based upon
the input voltage and supply voltage by the following
equation:
Duty Cycle = 100%
×
An internal DC voltage equal to:
V
DC
= (1.683
×
V
CTL
) + V
VALLEY
is compared to the oscillator voltage to produce the com-
pensated duty cycle. The transfer is set up so that when
V
CC
= 14V the duty cycle will equal V
CTL
divided by V
REG
.
For example at V
CC
= 14V, V
REG
= 5V and V
CTL
= 2.5V, the
duty cycle would be 50% at the output. This would place a
7V average voltage across the load. If V
CC
then drops to
10V, the IC would change the duty cycle to 70% and hence
keep the average load voltage at 7V.
Figure 1: Voltage Compensation
5V Linear Regulator
There is a 5V, 5mA linear regulator available at the V
REG
lead for external use. This voltage acts as a reference for
many internal and external functions. It has a drop out of
approximately 1.5V at room temperature.
Current Sense and Timer
The IC differentially monitors the load current on a cycle
by cycle basis at the I
SENSE+
and I
SENSE-
leads. The differen-
tial voltage across these two leads is amplified internally
and compared to the voltage at the I
ADJ
lead. The gain, A
V
is set internally and externally by the following equation:
A
V
=
=
The current limit (I
LIM
) is set by the external current sense
resistor (R
SENSE
) placed across the I
SENSE+
and I
SENSE-
ter-
minals and the voltage at the I
ADJ
lead.
I
LIM
=
×
The R
CS
resistors and C
CS
components form a differential
low pass filter which filters out high frequency noise gen-
erated by the switching of the external MOSFET and the
associated lead noise. R
CS
also forms and error term in the
gain of the I
LIM
equation because the I
SENSE+
and I
SENSE-
leads are low impedance inputs thereby creating a good
current sensing amplifier. Both leads source 50μA while
the chip is in run mode. I
ADJ
should be biased between 1V
and 4V. When the current through the external MOSFET
V
I(ADJ)
R
SENSE
1000 + R
CS
37000
37000
1000 + R
CS
V
I(ADJ)
I
SENSE+
- I
SENSE-
120%
100%
80%
60%
40%
20%
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
CTL Voltage (% of V
REG
)
D
V
CC
= 8V
V
CC
= 14V
V
CC
= 16V
2.8
×
V
CTL
V
CC
V
PEAK
- V
VALLEY
I
COSC
V
CC
R
OSC
V
CC
R
OSC
0.83
R
OSC
×
C
OSC
Theory Of Operation
相關PDF資料
PDF描述
CS4124 High Side PWM FET Controller
CS4161XN8 85mA Dual H-Bridge Odometer Driver with Divide by Select and UVLO
CS4161 85mA Dual H-Bridge Odometer Driver with Divide by Select and UVLO
CS4172XDWF16 Single Air-Core Gauge Driver
CS4172XDWFR16 Single Air-Core Gauge Driver
相關代理商/技術參數(shù)
參數(shù)描述
CS-4-12XA 制造商:Nidec Copal 功能描述:SWIT ROTARY SP SLOT J-HOOK 0.1A 16VAC 16VDC 0.5W - Bulk
CS-4-12XB 制造商:Nidec Copal 功能描述:SWIT ROTARY SP SCRWDRVR GW 0.1A 16VAC 16VDC 0.5W - Bulk 制造商:Nidec Copal 功能描述:Switches, rotary, surface mount,
CS-4-12XC 制造商:Nidec Copal 功能描述:SWIT ROTARY SP SLOT PC PINS 0.1A 16VAC 16VDC 0.5W - Bulk
CS-4-12XTA 功能描述:SWITCH ROTARY SPDT SMD J-LEAD RoHS:是 類別:開關 >> DIP 系列:CS-4 特色產品:RDM Series Rotary DIP Switch 標準包裝:70 系列:RDM 電路:十六進制 位置數(shù):16 觸點額定電壓:0.1A @ 42VDC 觸動器類型:用于工具旋轉 觸動器電平:凹槽式 安裝類型:通孔 方向:頂部觸動 可清洗:是 其它名稱:EG4977-5RDMAR16PIT
CS-4-12XTB 功能描述:SWITCH ROTARY SPDT SMD GULL RoHS:是 類別:開關 >> DIP 系列:CS-4 特色產品:RDM Series Rotary DIP Switch 標準包裝:70 系列:RDM 電路:十六進制 位置數(shù):16 觸點額定電壓:0.1A @ 42VDC 觸動器類型:用于工具旋轉 觸動器電平:凹槽式 安裝類型:通孔 方向:頂部觸動 可清洗:是 其它名稱:EG4977-5RDMAR16PIT