参数资料
| 型号： | LT1931AIS5#TRPBF |
| 厂商： | Linear Technology |
| 文件页数： | 4/12页 |
| 文件大小： | 0K |
| 描述： | IC REG INV 1A TSOT23-5 |
| 标准包装： | 2,500 |
| 类型： | 反相 |
| 输出数： | 1 |
| 输入电压： | 2.45 V ~ 16 V |
| PWM 型： | 电流模式 |
| 频率 - 开关： | 2.2MHz |
| 电流 - 输出： | 1A |
| 同步整流器： | 无 |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | SOT-23-5 细型，TSOT-23-5 |
| 包装： | 带卷 (TR) |
| 供应商设备封装： | TSOT-23-5 |
LT1931/LT1931A
BLOCK DIAGRA
V IN 5
R5
R6
V IN
80k
80k
+
COMPARATOR
1 SW
A1
V OUT
Q1
Q2
x10
R3
30k
–
g m
R C
C C
RAMP
GENERATOR
Σ
A2
R
LATCH
S
Q
DRIVER
+
Q3
0.01 ?
C PL
(OPTIONAL)
R1
(EXTERNAL)
NFB
R2
R4
150k
3 NFB
1.2MHz
OSCILLATOR
SHDN
4
SHUTDOWN
–
2 GND
OPERATIO
(EXTERNAL)
Figure 2
1931 BD
The LT1931 uses a constant frequency, current mode
control scheme to provide excellent line and load regula-
tion. Operation can be best understood by referring to the
Block Diagram in Figure 2. At the start of each oscillator
cycle, the SR latch is set, turning on the power switch Q3.
A voltage proportional to the switch current is added to a
stabilizing ramp and the resulting sum is fed into the
positive terminal of the PWM comparator A2. When this
voltage exceeds the level at the negative input of A2, the SR
latch is reset, turning off the power switch. The level at the
negative input of A2 is set by the error amplifier (g m ) and
is simply an amplified version of the difference between
the feedback voltage and the reference voltage of –1.255V.
In this manner, the error amplifier sets the correct peak
current level to keep the output in regulation. If the error
amplifier’s output increases, more current is taken from
the output; if it decreases, less current is taken. One
function not shown in Figure 2 is the current limit. The
switch current is constantly monitored and not allowed to
exceed the nominal value of 1.2A. If the switch current
reaches 1.2A, the SR latch is reset regardless of the state
of comparator A2. This current limit protects the power
switch as well as various external components connected
to the LT1931.
The Block Diagram for the LT1931A is identical except that
the oscillator is 2.2MHz and resistors R3 to R6 are one-half
the LT1931 values.
1931fa
4
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相关代理商/技术参数 |
参数描述 |
|---|---|
| LT1931ES5 | 制造商:未知厂家 制造商全称:未知厂家 功能描述: |
| LT1931ES5#PBF | 制造商:Linear Technology 功能描述:Conv DC-DC Single Inv 2.45V to 16V 5-Pin TSOT-23 制造商:Linear Technology 功能描述:IC SEMICONDUCTOR ((NS)) 制造商:Linear Technology 功能描述:IC, DC/DC CONVERTER, 5-TSOT-23; Primary Input Voltage:16V; No. of Outputs:1; Output Voltage:-12V; Output Current:350mA; No. of Pins:5; Operating Temperature Min:-40C; Operating Temperature Max:85C; MSL:MSL 1 - Unlimited ;RoHS Compliant: Yes |
| LT1931ES5#PBF | 制造商:Linear Technology 功能描述:IC |
| LT1931ES5#TR | 功能描述:IC REG INV 1A TSOT23-5 RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:2,500 系列:- 类型:升压（升压） 输出类型:可调式 输出数:1 输出电压:1.24 V ~ 30 V 输入电压:1.5 V ~ 12 V PWM 型:电流模式，混合 频率 - 开关:600kHz 电流 - 输出:500mA 同步整流器:无 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:8-SOIC（0.154"，3.90mm 宽） 包装:带卷 (TR) 供应商设备封装:8-SOIC |
| LT1931ES5#TRM | 功能描述:IC REG INV 1A TSOT23-5 RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:2,500 系列:- 类型:升压（升压） 输出类型:可调式 输出数:1 输出电压:1.24 V ~ 30 V 输入电压:1.5 V ~ 12 V PWM 型:电流模式，混合 频率 - 开关:600kHz 电流 - 输出:500mA 同步整流器:无 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:8-SOIC（0.154"，3.90mm 宽） 包装:带卷 (TR) 供应商设备封装:8-SOIC |
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