參數(shù)資料
型號: U2352B
英文描述: PWM Power Control for DC Loads
中文描述: PWM功率控制直流負(fù)載
文件頁數(shù): 3/8頁
文件大?。?/td> 110K
代理商: U2352B
U2352B
TELEFUNKEN Semiconductors
Rev. A1, 29-May-96
3 (8)
Pin Description
1
2
3
4
8
7
6
5
Osc
V
Contr
I
Set
S
2
OUT
V
S
Output
GND
S
2
IN
95 9701
Pin
1
2
3
Symbol
Osc
V
Contr
I
Set
Function
Oscillator
Control voltage input
Setpoint value current
monitoring
Output, current switch S
2
Input, current switch S
2
Ground
Output
Supply voltage
4
5
6
7
8
S
2
OUT
S
2
IN
GND
Output
V
S
Supply, Pin 8
Internal voltage limitation in the U2352B allows a simple
supply via a series resistor R
1
. This enables operation of
the circuit under different operating voltages. Supply
voltage between Pin 8 (V
S
) and Pin 6 (GND) builds up via
R
1
and is smoothed by C
1
.
The series resistor R
1
is calculated as follows:
V
Bmin
V
Smax
I
tot
R
1max
where
V
Bmin
= Minimum operating voltage
V
Smax
= Maximum supply voltage
I
tot
I
Smax
= Maximum current consumption of the IS
I
X
= Current consumption of the external elements
Various thresholds are derived from an internal reference
voltage source.
Voltage Monitoring
= I
Smax
+ I
X
During build-up and reduction of the operating voltage,
uncontrolled output pulses with excessively low ampli-
tude are suppressed by the internal monitoring circuit. All
latches are reset and the output of the load current detec-
tion Pin 4 is switched to ground.
Chip Temperature Monitoring
U2352B has integrated chip temperature monitoring
which switches off the output stage when a temperature
of approximately 140
°
C is reached. The device is not
enabled again until cooling has taken place and the supply
voltage has been switched off and then back on again.
Pulse Width Control, Pins 1 and 2
At the frequency-determining capacitor, C
osc
, at Pin 1,
switching over of two internal current sources gives rise
to a triangular voltage which comparator, K
1
, compares
with the control voltage at Pin 2. If the voltage, V
1
, is
more negative than the control voltage V
2
, the output
stage is switched on via the output stage logic. When C
osc
is charged, the whole process then runs in reverse order
(see figure 3).
Load Current Monitoring, Pins 3, 4, 5
Load current can be measured with the aid of an external
shunt resistor, but this is only appropriate for decreased
loads due to additional power loss and component size
and costs. This involves the shunt voltage being fed
directly to Pin 4 via a protective resistor (see figure 5).
In order to save component costs and additional power
loss, the integrated load current monitoring allows the
load current to be directly measured via the voltage drop
at the on-state resistance, R
DS(on)
, of the FET, without an
additional shunt resistor. The drain voltage of the FET is
supplied via an external protective resistor to Pin 5.
During the off-state of the FET, a diode clamp circuit
protects the detection input, Pin 5. In the on state, the load
current flowing through the FET generates a
corresponding voltage drop at its R
DS(on)
, which is in turn
converted into a current at Pin 5 by the protective resistor.
This current reaches the integration element at Pin 4 via
the switch S
2
, which is only closed in the on-state of the
FET. If the voltage at Pin 4 exceeds the setpoint value set
at Pin 3, as a result of a high load current, the shutdown
latch is set and the output stage is blocked. To enable the
circuit again, it is necessary to switch the operating
voltage off and then back on again.
Switch-off behavior is adjusted with the resistors at Pin 4
and Pin 5 and also with the capacitor at Pin 4.
相關(guān)PDF資料
PDF描述
U2391B Quartz Controlled Pulse Generator
U243B-FP Warning or Car-Direction Indicator
U2642B Intermittent- and Wipe/Wash Control for Wiper Systems
U2642B-FP Intermittent- and Wipe/Wash Control for Wiper Systems
U267BG To drive LED-displays with 5 or 10 diodes
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
U2-353 制造商:OTTO Engineering Inc 功能描述:S/A U2-352 EXP W/
U2353A 制造商:Agilent Technologies 功能描述:DATA ACQUISITION MODULE 16 CHANNEL 制造商:Agilent Technologies 功能描述:USB MODULAR DATA ACQUISITION; No. of Channels:16; Sampling Rate:1MSPS; Input Voltage Max:12V; Input Current Max:10A; Bandwidth:400kHz; External Height:44mm; External Width:120mm; External Depth:182.4mm; Sample Rate:500 kSa/s ;RoHS Compliant: NA 制造商:Agilent Technologies 功能描述:16-Channel 500kSa/s USB Data Acquisition
U2-354 制造商:OTTO Engineering Inc 功能描述:S/A U2-278 EXCEPT WATERTIGHT
U2354A 制造商:Agilent Technologies 功能描述:DATA ACQUISITION MODULE 16 CHANNEL 制造商:Agilent Technologies 功能描述:USB MODULAR DATA ACQUISITION; No. of Channels:16; Sampling Rate:1MSPS; Input Voltage Max:12V; Input Current Max:10A; Bandwidth:400kHz; External Height:44mm; External Width:120mm; External Depth:182.4mm; Sample Rate:500 kSa/s ;RoHS Compliant: NA
U2355A 制造商:Agilent Technologies 功能描述:Bulk 制造商:Agilent Technologies 功能描述:DATA ACQUISITION MODULE 64 CHANNEL 制造商:Agilent Technologies 功能描述:USB MODULAR DATA ACQUISITION; No. of Channels:16; Sampling Rate:250kSPS; Input Voltage Max:12V; Input Current Max:10A; Bandwidth:400kHz; External Height:44mm; External Width:120mm; External Depth:182.4mm; Sample Rate:250 kSa/s ;RoHS Compliant: NA 制造商:Agilent Technologies 功能描述:64-Channel 250kSa/s USB Data Acquisition