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English3A连续输出电流CXSD62145高/低边MOSFET PFM/PWM模式操作 固定340kHz开关频率 低ESR陶瓷输出电容稳定
1.产品概述 2.产品特点
3.应用范围 4.下载产品资料PDF文档
5.产品封装图 6.电路原理图
7.功能概述 8.相关产品
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一,产品概述(General Description) LCD Monitor/TV Set-Top Box 四.下载产品资料PDF文档 需要详细的PDF规格书请扫一扫微信联系我们，还可以获得免费样品以及技术支持！
五,产品封装图 (Package)
六.电路原理图
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七,功能概述
Main Control Loop
The CXSD62144 is a constant frequency current mode switching regulator. During normal operation, the inter-
nal N-channel power MOSFET is turned on each cycle when the oscillator sets an internal RS latch and would
be turned off when an internal current comparator (ICMP) resets the latch. The peak inductor current at which ICMP
resets the RS latch is controlled by the voltage on the COMP pin, which is the output of the error amplifier
(EAMP). An external resistive divider connected between VOUT and ground allows the EAMP to receive an output
feedback voltage VFB at FB pin. When the load current increases, it causes a slight decrease in VFB relative to
the 0.925V reference, which in turn causes the COMP voltage to increase until the average inductor current
matches the new load current.
VIN Power-On-Reset (POR) and EN Under-voltage Lockout
The CXSD62144 keep monitoring the voltage on VIN pin to prevent wrong logic operations which may occur when
VIN voltage is not high enough for the internal control circuitry to operate. The VIN POR has a rising threshold
of 4.05V (typical) with 0.3V of hysteresis.
An external under-voltage lockout (UVLO) is sensed atthe EN pin. The EN UVLO has a rising threshold of 2.5V
with 0.2V of hysteresis. The EN pin should be connected a resistor divider from VIN to EN .After the VIN and EN
voltages exceed their respective voltage thresholds, the IC starts a start-up process and then ramps up the output
voltage to the setting of output voltage.
Over-Temperature Protection (OTP)
The over-temperature circuit limits the junction tempera-ture of the CXSD62144 When the junction temperature ex-
ceeds TJ =+160oC, a thermal sensor turns off the power MOSFET, allowing the device to cool down. The thermal
sensor allows the converter to start a start-up process and regulate the output voltage again after the junction
temperature cools by 50oC.
The OTP designed with a 50 oC hysteresis lowers the average T J during c ontinuous thermal overload conditions,
increasing life time of the IC.
Enable/Shutdown
Driving EN to ground places the CXSD62144 in shutdown.When in shutdown, the internal N-Channel power MOSFET turns off, all internal circuitry shuts down and the quies-cent supply current reduces to 0.3μA.
Current-Limit Protection
The CXSD62144 monitors the output current, flowing through the N-Channel power MOSFET, and limits the
IC from damages during overload, short-circuit and over-voltage conditions.
Frequency Foldback
The foldback frequency is controlled by the FB voltage.When the FB pin voltage is under 0.6V, the frequency of
the oscillator will be reduced to 110kHz. This lower fre-quency allows the inductor current to safely discharge,
thereby preventing current runaway. The oscillator’s fre-quency will switch to its designed rate when the feedback
voltage on FB rises above the rising frequency foldback threshold (0.6V, typical) again.
Over-Voltage Protection
The over-voltage function monitors the output voltage by FB pin. When the FB voltage increase over 120% of the
reference voltage, the over-voltage protection compara-tor will force the high-and low-side MOSFET gate driver
off. As soon as the output voltage is within regulation, the OVP comparator is disengaged. The chip will restore its
normal operation.
八,相关产品 更多同类产品.......
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Switching Regulator > Buck Converter |
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Part_No |
Package |
Architectu |
No.of PWM Outpu |
Drive Lout (A) |
Vin(V) |
Fmax Khz |
Vref (V) |
R-Top (milohm) |
R-Sync (milohm) |
Iq (No load) (uA) |
|
|
min |
max |
||||||||||
|
TQFN5x6-28 |
CM |
1 |
5 |
4.5 |
26 |
380 |
0.8 |
50 |
20 |
1000 |
|
|
SOP-8 |
CM |
1 |
2 |
4.5 |
26 |
380 |
0.8 |
100 |
1000 |
||
|
SOP-8P |
CM |
1 |
4 |
4.5 |
26 |
380 |
0.8 |
80 |
1000 |
||
|
SOT23-5|TSOT23-5 |
CM |
1 |
1 |
2.7 |
6 |
1500 |
0.6 |
280 |
250 |
25 |
|
|
SOT23-5 |
CM |
1 |
1 |
2.7 |
6 |
1500 |
0.6 |
280 |
250 |
||
|
SOP-8 |
CM |
1 |
3 |
4.3 |
14 |
500 |
0.8 |
70 |
70 |
500 |
|
|
SOP-8P |
CM |
1 |
3 |
4.3 |
14 |
500 |
0.8 |
55 |
45 |
500 |
|
|
TDFN3x3-10 |
3 |
2.6 |
5.5 |
2000 |
0.8 |
110 |
110 |
460 |
|||
|
TDFN3x3-10 |
CM |
2 |
1 |
2.7 |
6 |
1500 |
0.6 |
280 |
250 |
500 |
|
|
TDFN3x3-10 |
CM |
2 |
1 |
2.7 |
6 |
1500 |
0.6 |
280 |
250 |
||
|
TDFN2x2-6 |
CM |
1 |
1 |
2.7 |
6 |
1500 |
0.6 |
280 |
250 |
25 |
|
|
TDFN2x2-6 |
CM |
1 |
1 |
2.7 |
6 |
1500 |
0.6 |
280 |
250 |
||
|
TDFN3x3-12 |
CM |
2 |
1 |
2.7 |
6 |
1500 |
0.6 |
280 |
250 |
25 |
|
|
TDFN3x3-12 |
CM |
2 |
1 |
2.7 |
6 |
1500 |
0.6 |
280 |
250 |
||
|
TDFN 3x3 12 |
CM |
2 |
1 |
3 |
5.5 |
1500 |
0.6 |
280 |
250 |
30 |
|
|
TQFN3x3-20 |
CM |
3 |
2 |
2.9 |
5.5 |
1500 |
0.6 |
- |
- |
300 |
|
|
TDFN2x2-8 |
CM |
1 |
1 |
3.3 |
8 |
1500 |
0.6 |
280 |
250 |
25 |
|
|
SOP-8 |
CM |
1 |
2 |
4.5 |
24 |
340 |
0.925 |
110 |
110 |
1900 |
|
|
SOP-8P |
CM |
1 |
3 |
4.5 |
24 |
340 |
0.925 |
110 |
110 |
1900 |
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