参数资料
型号: REG101NA-2.85/3K
厂商: TEXAS INSTRUMENTS INC
元件分类: 固定正电压单路输出LDO稳压器
英文描述: 2.85 V FIXED POSITIVE LDO REGULATOR, 0.13 V DROPOUT, PDSO5
封装: GREEN, PLASTIC, SOT-23, 5 PIN
文件页数: 2/23页
文件大小: 719K
代理商: REG101NA-2.85/3K
REG101
10
SBVS026D
FIGURE 4. Block Diagram.
FIGURE 5. Output Noise versus Noise Reduction Capacitor.
ENABLE
The Enable pin is active HIGH and compatible with stan-
dard TTL-CMOS levels. Inputs below 0.5V (max) turn the
regulator off and all circuitry is disabled. Under this condi-
tion, ground pin current drops to approximately 10nA. When
a pull-up resistor is used, and operation down to VIN = 1.8V
is required, use values < 50k
.
OUTPUT NOISE
A precision band-gap reference is used for the internal
reference voltage, VREF. This reference is the dominant
noise source within the REG101 and it generates approxi-
mately 29
Vrms in the 10Hz to 100kHz bandwidth at the
reference output. The regulator control loop gains up the
reference noise, so that the noise voltage of the regulator is
approximately given by:
V = 29 Vrms
R+ R
R2
Vrms
V
N
1
2
OUT
REF
= 29
Since the value of VREF is 1.267V, this relationship reduces to:
V= 23
Vrms
V
N
OUT
Connecting a capacitor, CNR, from the Noise Reduction (NR)
pin to ground, as shown in Figure 4, forms a low-pass filter for
the voltage reference. For CNR = 10nF, the total noise in the
10Hz to 100kHz bandwidth is reduced by approximately a
factor of 2.8 for VO = 3.3V. This noise reduction effect is
shown in Figure 5 and as “RMS Noise Voltage vs CNR” in the
Typical Characteristics section.
Noise can be further reduced by carefully choosing an
output capacitor, COUT. Best overall noise performance is
achieved with very low (< 0.22
F) or very high (> 2.2F)
values of COUT. See “RMS Noise Voltage vs COUT” in the
Typical Characteristics section.
The REG101 utilizes an internal charge pump to develop an
internal supply voltage sufficient to drive the gate of the
DMOS pass element above VIN. The charge-pump switch-
ing noise (nominal switching frequency = 2MHz) is not
measurable at the output of the regulator over most values of
COUT and IOUT.
The REG101 adjustable version does not have the noise-
reduction pin available, however, the adjust pin is the sum-
ming junction of the error amplifier. A capacitor, CFB,
connected from the output to the adjust pin will reduce both
the output noise and the peak error from a load transient. See
the typical characteristics for output noise performance.
Over Current
Over Temp
Protection
V
REF
(1.26V)
Low Noise
Charge Pump
DMOS
Pass
Transistor
R
1
NOTE: R
1 and R2 are internal
on fixed output versions.
V
OUT
Adj
(Adjustable
Versions)
R
2
NR
(fixed output
versions only)
Enable
REG101
V
IN
C
NR
(optional)
110
1k
100
10k
110
100
90
80
70
60
50
40
30
20
Noise
Voltage
(
Vrms)
C
NR (pF)
RMS NOISE VOLTAGE vs C
NR
C
NR = 0F
10Hz < BW < 100kHz
REG101-5.0
REG101-2.5
REG101-3.3
相关PDF资料
PDF描述
REG101NA-3.3/3K 3.3 V FIXED POSITIVE LDO REGULATOR, 0.13 V DROPOUT, PDSO5
REG101NA-3/3K 3 V FIXED POSITIVE LDO REGULATOR, 0.13 V DROPOUT, PDSO5
REG101UA-A/2K5G4 2.5 V-5.5 V ADJUSTABLE POSITIVE LDO REGULATOR, 0.13 V DROPOUT, PDSO8
REG102GA2.85/2K5G4 2.85 V FIXED POSITIVE LDO REGULATOR, 0.27 V DROPOUT, PDSO6
REG103UA-A/2K5 1.295 V-5.5 V ADJUSTABLE POSITIVE LDO REGULATOR, 0.2 V DROPOUT, PDSO8
相关代理商/技术参数
参数描述
REG101NA-3.0/250 制造商:TI 制造商全称:Texas Instruments 功能描述:DMOS 100mA Low-Dropout Regulator
REG101NA-3.0/250G4 制造商:TI 制造商全称:Texas Instruments 功能描述:DMOS 100mA Low-Dropout Regulator
REG101NA-3.0/3K 制造商:TI 制造商全称:Texas Instruments 功能描述:DMOS 100mA Low-Dropout Regulator
REG101NA-3.0/3KG4 制造商:TI 制造商全称:Texas Instruments 功能描述:DMOS 100mA Low-Dropout Regulator
REG101NA-3.3/250 功能描述:低压差稳压器 - LDO DMOS 100mA LDO Reg RoHS:否 制造商:Texas Instruments 最大输入电压:36 V 输出电压:1.4 V to 20.5 V 回动电压(最大值):307 mV 输出电流:1 A 负载调节:0.3 % 输出端数量: 输出类型:Fixed 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-20