参数资料
| 型号： | LT1764AEQ-1.5 |
| 厂商： | Linear Technology |
| 文件页数： | 12/20页 |
| 文件大小： | 0K |
| 描述： | IC REG LDO 1.5V 3A DDPAK-5 |
| 产品培训模块： | More Information on LDOs |
| 标准包装： | 50 |
| 稳压器拓扑结构： | 正，固定式 |
| 输出电压： | 1.5V |
| 输入电压： | 2.7 V ~ 20 V |
| 电压 - 压降（标准）： | 0.34V @ 3A |
| 稳压器数量： | 1 |
| 电流 - 输出： | 3A |
| 电流 - 限制（最小）： | 3.1A |
| 工作温度： | -40°C ~ 125°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | TO-263-6，D²Pak（5 引线+接片），TO-263BA |
| 供应商设备封装： | D2PAK-5 |
| 包装： | 管件 |
| 产品目录页面： | 1329 (CN2011-ZH PDF) |
LT1764A Series
APPLICATIO S I FOR ATIO
ing the capacitor value improves the stability and reduces
the ringing. Table 1 gives some recommended values of
ESR to minimize ringing caused by fast, hard current
transitions.
Table 1. Capacitor Minimum ESR
V OUT 10 μ F 22 μ F 47 μ F 100 μ F
1.2V 10m ? 5m ? 3m ? 0m ?
1.5V 7m ? 5m ? 3m ? 0m ?
1.8V 5m ? 5m ? 3m ? 0m ?
2.5V 0m ? 0m ? 0m ? 0m ?
3.3V 0m ? 0m ? 0m ? 0m ?
≥ 5V 0m ? 0m ? 0m ? 0m ?
Figures 3 through 8 show the effect of ESR on the transient
response of the regulator. These scope photos show the
transient response for the LT1764A at three different
output voltages with various capacitors and various val-
ues of ESR. The output load conditions are the same for all
traces. In all cases there is a DC load of 1A. The load steps
up to 2A at the first transition and steps back to 1A at the
second transition.
At the worst case point of 1.2V OUT with 10 μ F C OUT
(Figure 3), a minimum amount of ESR is required. While
5m ? is enough to eliminate most of the ringing, a value
closer to 20m ? provides a more optimum response. At
2.5V output with 10 μ F C OUT (Figure 4) the output rings
at the transitions with 0 ? ESR but still settles to within
10mV in 20 μ s after the 1A load step. Once again a small
value of ESR will provide a more optimum response.
At 5V OUT with 10 μ F C OUT (Figure 5) the response is well
damped with 0 ? ESR.
With a C OUT of 100 μ F at 0 ? ESR and an output of 1.2V
(Figure 6), the output rings although the amplitude is only
10mV p-p . With C OUT of 100 μ F it takes only 5m ? to 20m ?
of ESR to provide good damping at 1.2V output. Perfor-
mance at 2.5V and 5V output with 100 μ F C OUT shows sim-
ilar characteristics to the 10 μ F case (see Figures 7-8). At
2.5V OUT 5m ? to 20m ? can improve transient response.
At 5V OUT the response is well damped with 0 ? ESR.
Capacitor types with inherently higher ESR can be com-
bined with 0m ? ESR ceramic capacitors to achieve both
good high frequency bypassing and fast settling time.
Figure 9 illustrates the improvement in transient response
that can be seen when a parallel combination of ceramic
and POSCAP capacitors are used. The output voltage is at
the worst case value of 1.2V. Trace A, is with a 10 μ F
ceramic output capacitor and shows significant ringing
with a peak amplitude of 25mV. For Trace B, a 22 μ F/45m ?
POSCAP is added in parallel with the 10 μ F ceramic. The
output is well damped and settles to within 10mV in less
than 5 μ s.
For Trace C, a 100 μ F/35m ? POSCAP is connected in
parallel with the 10 μ F ceramic capacitor. In this case the
peak output deviation is less than 20mV and the output
settles in about 5 μ s. For improved transient response the
value of the bulk capacitor (tantalum or aluminum electro-
lytic) should be greater than twice the value of the ceramic
capacitor.
Tantalum and Polytantalum Capacitors
There is a variety of tantalum capacitor types available,
with a wide range of ESR specifications. Older types have
ESR specifications in the hundreds of m ? to several
Ohms. Some newer types of polytantalum with multi-
electrodes have maximum ESR specifications as low as
5m ? . In general the lower the ESR specification, the larger
the size and the higher the price. Polytantalum capacitors
have better surge capability than older types and generally
lower ESR. Some types such as the Sanyo TPE and TPB
series have ESR specifications in the 20m ? to 50m ?
range, which provide near optimum transient response.
Aluminum Electrolytic Capacitors
Aluminum electrolytic capacitors can also be used with the
LT1764. These capacitors can also be used in conjunction
with ceramic capacitors. These tend to be the cheapest
and lowest performance type of capacitors. Care must be
used in selecting these capacitors as some types can have
ESR which can easily exceed the 3 ? maximum value.
1764afb
12
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相关代理商/技术参数 |
参数描述 |
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| LT1764AEQ-2.5 | 功能描述:IC REG LDO 2.5V 3A DDPAK-5 RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - 线性 系列:- 标准包装:1 系列:- 稳压器拓扑结构:正，固定式 输出电压:3V 输入电压:2.3 V ~ 5.5 V 电压 - 压降（标准）:0.035V @ 150mA 稳压器数量:2 电流 - 输出:150mA 电流 - 限制（最小）:300mA 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:6-UFDFN 裸露焊盘，6-TMLF? 供应商设备封装:6-TMLF?（1.6x1.6） 包装:Digi-Reel® 产品目录页面:1104 (CN2011-ZH PDF) 其它名称:576-3018-6 |
| LT1764AEQ-2.5#PBF | 功能描述:IC REG LDO 2.5V 3A DDPAK-5 RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 线性 系列:- 标准包装:1 系列:- 稳压器拓扑结构:正，固定式 输出电压:8V 输入电压:10.5 V ~ 23 V 电压 - 压降（标准）:1.7V @ 40mA 稳压器数量:1 电流 - 输出:100mA（最小值） 电流 - 限制（最小）:- 工作温度:0°C ~ 125°C 安装类型:表面贴装 封装/外壳:8-SOIC（0.154"，3.90mm 宽） 供应商设备封装:8-SOIC 包装:剪切带 (CT) 产品目录页面:1075 (CN2011-ZH PDF) 其它名称:296-24390-1 |
| LT1764AEQ-2.5#PBF | 制造商:Linear Technology 功能描述:Linear Voltage Regulator IC 制造商:Linear Technology 功能描述:IC, LDO VOLT REG, 2.5V, 3A, D2-PAK-5 |
| LT1764AEQ-2.5#TR | 功能描述:IC REG LDO 2.5V 3A DDPAK-5 RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - 线性 系列:- 标准包装:1 系列:- 稳压器拓扑结构:正，固定式 输出电压:3V 输入电压:2.3 V ~ 5.5 V 电压 - 压降（标准）:0.035V @ 150mA 稳压器数量:2 电流 - 输出:150mA 电流 - 限制（最小）:300mA 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:6-UFDFN 裸露焊盘，6-TMLF? 供应商设备封装:6-TMLF?（1.6x1.6） 包装:Digi-Reel® 产品目录页面:1104 (CN2011-ZH PDF) 其它名称:576-3018-6 |
| LT1764AEQ-2.5#TRPBF | 功能描述:IC REG LDO 2.5V 3A DDPAK-5 RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 线性 系列:- 标准包装:1 系列:- 稳压器拓扑结构:正，固定式 输出电压:3V 输入电压:2.3 V ~ 5.5 V 电压 - 压降（标准）:0.035V @ 150mA 稳压器数量:2 电流 - 输出:150mA 电流 - 限制（最小）:300mA 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:6-UFDFN 裸露焊盘，6-TMLF? 供应商设备封装:6-TMLF?（1.6x1.6） 包装:Digi-Reel® 产品目录页面:1104 (CN2011-ZH PDF) 其它名称:576-3018-6 |
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