- 您现在的位置：买卖IC网 > PDF目录170207 > CS-51031D8 (ON SEMICONDUCTOR) 1 A SWITCHING CONTROLLER, 700 kHz SWITCHING FREQ-MAX, PDSO8 PDF资料下载
参数资料
| 型号： | CS-51031D8 |
| 厂商： | ON SEMICONDUCTOR |
| 元件分类： | 稳压器 |
| 英文描述： | 1 A SWITCHING CONTROLLER, 700 kHz SWITCHING FREQ-MAX, PDSO8 |
| 封装： | 0.150 INCH, SO-8 |
| 文件页数： | 4/8页 |
| 文件大小： | 156K |
| 代理商： | CS-51031D8 |
CS-51031
4
Block Diagram
G5
COSC
CS
VREF
VC
VGATE
PGnd
VFB
Gnd
R
S
2.5V
1.5V
1.25V
1.15V
Q
F2
G2
G1
A1
A6
RG
VCC
3.3V
VCCOK
A3
2.4V
G3
VREF = 3.3V
A2
2.5V
1.5V
IC
7IC
VREF
VCC
+
-
IT
+
Q
IT
5
IT
55
G4
Fault
Comp
+
-
+
-
+
-
A4
0.7V
2.3V
Q
R
Q
S
F1
Slow Discharge
Comparator
Slow Discharge
Flip-Flop
CS Charge
Sense
Comparator
CS
Comparator
Oscillator
Comparator
VFB
Comparator
VGATE
Flip-Flop
Hold
Off
Comp
Control Scheme
The CS-51031 monitors and the output voltage to deter-
mine when to turn on the PFET. If VFB falls below the inter-
nal reference voltage of 1.25V during the oscillators charge
cycle, the PFET is turned on and remains on for the dura-
tion of the charge time. The PFET gets turned off and
remains off during the oscillators discharge time with the
maximum duty cycle to 80%. It requires 7mV typical, and
20mV maximum ripple on the VFB pin is required to oper-
ate. This method of control does not require any loop sta-
bility compensation.
Startup
The CS-51031 has an externally programmable soft start
feature that allows the output voltage to come up slowly,
preventing voltage overshoot on the output.
At startup, the voltage on all pins is zero. As VCC rises, the
VC voltage along with the internal resistor RG keeps the
PFET off. As VCC and VC continue to rise, the oscillator
capacitor (COSC ) and the Soft start/Fault Timing capacitor
(CS) charges via internal current sources. COSC gets
charged by the current source IC and CS gets charged by
the IT source combination described by:
ICS = IT -
( + ).
The internal Holdoff Comparator ensures that the external
PFET is off until VCS > 0.7V, preventing the GATE flip-flop
(F2) from being set. This allows the oscillator to reach its
operating frequency before enabling the drive output. Soft
start is obtained by clamping the VFB comparators (A6)
reference input to approximately 1/2 of the voltage at the
CS pin during startup, permitting the control loop and the
output voltage to slowly increase. Once the CS pin charges
above the Holdoff Comparator trip point of 0.7V, the low
feedback to the VFB Comparator sets the GATE flip-flop
during COSC s charge cycle. Once the GATE flip-flop is set,
VGATE goes low and turns on the PFET. When VCS exceeds
IT
5
IT
55
Theory of Operation
Circuit Description
Figure 1: Block Diagram for CS-51031
相关PDF资料 |
PDF描述 |
|---|---|
| CS020B12C-C0 | SINGLE COLOR LED, BLUE, 1.3 mm |
| CS020Y08C-C0 | SINGLE COLOR LED, YELLOW, 1.3 mm |
| CS100G40C-C0 | SINGLE COLOR LED, GREEN, 2.4 mm |
| CS100R14C-C0 | SINGLE COLOR LED, RED, 2.4 mm |
| CS11LMSD5NBF-SMT-20F-6H | ROTARY OPTICAL POSITION ENCODER |
相关代理商/技术参数 |
参数描述 |
|---|---|
| CS51031ED8 | 制造商:未知厂家 制造商全称:未知厂家 功能描述:Voltage-Mode SMPS Controller |
| CS51031EDR8 | 制造商:未知厂家 制造商全称:未知厂家 功能描述:Voltage-Mode SMPS Controller |
| CS51031EN8 | 制造商:未知厂家 制造商全称:未知厂家 功能描述:Voltage-Mode SMPS Controller |
| CS51031GD8 | 功能描述:DC/DC 开关控制器 Fast PFET Buck RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK |
| CS51031GD8G | 功能描述:DC/DC 开关控制器 Fast PFET Buck RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK |
发布紧急采购，3分钟左右您将得到回复。