参数资料
| 型号： | LT1964IDD#PBF |
| 厂商： | Linear Technology |
| 文件页数： | 11/16页 |
| 文件大小： | 0K |
| 描述： | IC REG LDO NEG ADJ .2A 8DFN |
| 产品培训模块： | More Information on LDOs |
| 标准包装： | 121 |
| 稳压器拓扑结构： | 负，可调式 |
| 输出电压： | -1.22 V ~ -20 V |
| 输入电压： | -1.9 V ~ -20 V |
| 电压 - 压降（标准）： | 0.34V @ 200mA |
| 稳压器数量： | 1 |
| 电流 - 输出： | 200mA |
| 电流 - 限制（最小）： | 220mA |
| 工作温度： | -40°C ~ 125°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 8-WFDFN 裸露焊盘 |
| 供应商设备封装： | 8-DFN-EP（3x3） |
| 包装： | 管件 |
LT1964
APPLICATIONS INFORMATION
The LT1964 is a 200mA negative low dropout regulator with
micropower quiescent current and shutdown. The device
is capable of supplying 200mA at a dropout voltage of
340mV. Output voltage noise can be lowered to 30μV RMS
over a 10Hz to 100kHz bandwidth with the addition of a
0.01μF reference bypass capacitor. Additionally, the refer-
ence bypass capacitor will improve transient response of
the regulator, lowering the settling time for transient load
conditions. The low operating quiescent current (30μA)
drops to 3μA in shutdown. In addition to the low quies-
cent current, the LT1964 incorporates several protection
features which make it ideal for use in battery-powered
systems. In dual supply applications where the regulator
load is returned to a positive supply, the output can be
pulled above ground by as much as 20V and still allow
the device to start and operate.
the formula in Figure 1. The value of R1 should be less
than 250k to minimize errors in the output voltage caused
by the ADJ pin bias current. Note that in shutdown the
output is turned off and the divider current will be zero.
Curves of ADJ Pin Voltage vs Temperature and ADJ Pin Bias
Current vs Temperature appear in the Typical Performance
Characteristics section.
The adjustable device is tested and speci?ed with the ADJ
pin tied to the OUT pin and a 5μA DC load (unless otherwise
speci?ed) for an output voltage of –1.22V. Speci?cations
for output voltages greater than –1.22V will be propor-
tional to the ratio of the desired output voltage to –1.22V;
(V OUT /–1.22V). For example, load regulation for an output
current change of 1mA to 200mA is 2mV typical at V OUT =
–1.22V. At V OUT = –12V, load regulation is:
(–12V/–1.22V) ? (2mV) = 19.6mV
Adjustable Operation
The adjustable version of the LT1964 has an output volt-
age range of –1.22V to –20V. The output voltage is set by
the ratio of two external resistors as shown in Figure 1.
The device servos the output to maintain the voltage at
the ADJ pin at –1.22V referenced to ground. The current
in R1 is then equal to –1.22V/R1 and the current in R2 is
the current in R1 plus the ADJ pin bias current. The ADJ
pin bias current, 30nA at 25°C, ?ows through R2 out of
the ADJ pin. The output voltage can be calculated using
Bypass Capacitance and Low Noise Performance
The LT1964 may be used with the addition of a bypass
capacitor from V OUT to the BYP pin to lower output voltage
noise. A good quality low leakage capacitor is recom-
mended. This capacitor will bypass the reference of the
LT1964, providing a low frequency noise pole. The noise
pole provided by this bypass capacitor will lower the out-
put voltage noise to as low as 30μV RMS with the addition
of a 0.01μF bypass capacitor. Using a bypass capacitor
has the added bene?t of improving transient response.
With no bypass capacitor and a 10μF output capacitor, a
V IN
IN
GND
ADJ
LT1964
OUT
R1
R2
+
V OUT
1964 F01
–10mA to –200mA load step will settle to within 1% of
its ?nal value in less than 100μs. With the addition of a
0.01μF bypass capacitor, the output will stay within 1%
for the same –10mA to –200mA load step (see LT1964-5
Transient Response in the Typical Characteristics section).
V OUT = –1.22V(1 + ) – (I ADJ )(R2)
R2
R1
V ADJ = –1.22V
I ADJ = 30nA AT 25°C
OUTPUT RANGE = –1.22V TO –20V
Figure 1. Adjustable Operation
However, regulator start-up time is proportional to the size
of the bypass capacitor.
Higher values of output voltage noise may be measured
if care is not exercised with regard to circuit layout and
testing. Crosstalk from nearby traces can induce unwanted
noise onto the output of the LT1964-X.
1964fb
11
相关PDF资料 |
PDF描述 |
|---|---|
| MIC29202WU | IC REG LDO ADJ .4A TO263-5 |
| RBA50DTKT | CONN EDGECARD 100PS DIP .125 SLD |
| 1210-153J | INDUCTOR FERRITE CORE 15UH SMD |
| HMM15DRKF | CONN EDGECARD 30POS DIP .156 SLD |
| HSM18DRAN | CONN EDGECARD 36POS R/A .156 SLD |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LT1964IDDTR | 制造商:LINER 制造商全称:Linear Technology 功能描述:200mA, Low Noise,Low Dropout Negative Micropower Regulator |
| LT1964IDDTRPBF | 制造商:LINER 制造商全称:Linear Technology 功能描述:200mA, Low Noise,Low Dropout Negative Micropower Regulator |
| LT1964IS5-5 | 制造商:LINER 制造商全称:Linear Technology 功能描述:200mA, Low Noise,Low Dropout Negative Micropower Regulator |
| LT1964IS5-5#PBF | 制造商:Linear Technology 功能描述:LDO FIXED 0.34VDO -5V 200M 制造商:Linear Technology 功能描述:LDO, FIXED, 0.34VDO, -5V, 200MA, 5SOT23 制造商:Linear Technology 功能描述:LDO, FIXED, -5V, 200mA, SOT-23-5; Primary Input Voltage:-1.9V; Output Voltage Fixed:-5V; Dropout Voltage Vdo:340mV; No. of Pins:5; Output Current:200mA; Operating Temperature Min:-40C; Operating Temperature Max:125C ;RoHS Compliant: Yes |
| LT1964IS5-5#TRM | 制造商:Linear Technology 功能描述:LDO Regulator Neg -5V 0.2A 5-Pin TSOT-23 T/R |
发布紧急采购，3分钟左右您将得到回复。