参数资料
型号: MAX1587AETL+T
厂商: Maxim Integrated Products
文件页数: 28/30页
文件大小: 0K
描述: IC POWER MANAGEMENT 40-TQFN
产品培训模块: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
标准包装: 2,500
应用: 手持/移动设备
电源电压: 2.6 V ~ 5.5 V
工作温度: -40°C ~ 85°C
安装类型: 表面贴装
封装/外壳: 40-WFQFN 裸露焊盘
供应商设备封装: 40-TQFN-EP(6x6)
包装: 带卷 (TR)
High-Efficiency, Low-I Q PMICs with
Dynamic Core for PDAs and Smart Phones
Rechargeable Li+ Backup Battery
If more backup power is needed and a primary cell has
inadequate capacity, a rechargeable lithium cell can be
MAIN
POWER
4.7 μ F
D1
1N4148
IN
BKBT
MAX1586
MAX1587
accommodated as shown in Figure 9. A series resistor
and diode charge the cell when the 3.3V V1 supply is
active. In addition to biasing V7, the rechargeable bat-
tery may be required to also power other supplies.
V7
1 μ F
Figure 8. BKBT connection when no backup battery is used, or
if an alternate backup scheme, not involving the
MAX1586/MAX1587, is used.
Rechargeable NiMH Backup Battery
In some systems, a NiMH battery may be desired for
backup. Usually this requires multiple cells because
the typical NiMH cell voltage is only 1.2V. By adding a
small DC-DC converter (MAX1724), the low-battery
voltage is boosted to 3V to bias BKBT (Figure 10). The
DC-DC converter’s low operating current (1.5μA typ)
allows it to remain on constantly so the 3V BKBT bias is
always present. A resistor and diode trickle charge the
NiMH cell when the main power is present.
MAIN
POWER
4.7 μ F
1k Ω
IN
V1
MAX1586
MAX1587
PCB Layout and Routing
Good PCB layout is important to achieve optimal perfor-
mance. Conductors carrying discontinuous currents and
any high-current path should be made as short and wide
as possible. A separate low-noise ground plane contain-
ing the reference and signal grounds should connect to
the power-ground plane at only one point to minimize the
1-CELL
Li+ RECHARGEABLE
BACKUP BATTERY
4.7 μ F
1 μ F
BKBT
V7
effects of power-ground currents. Typically, the ground
planes are best joined right at the IC.
Keep the voltage feedback network very close to the
IC, preferably within 0.2in (5mm) of the FB_ pin. Nodes
with high dV/dt (switching nodes) should be kept as
small as possible and should be routed away from
Figure 9. A 1-cell rechargeable Li+ battery provides more back-
up power when a primary cell is insufficient. The cell is charged
to 3.3V when V1 is active. Alternately, the battery can be
charged from IN if the voltages are appropriate for the cell type.
high-impedance nodes such as FB_. Refer to the
MAX1586 or MAX1587 evaluation kit data sheets for a
full PCB example.
1N4148
10k Ω
MAIN
POWER
MURATA
LQH32C 10 μ H
4.7 μ F
IN
1-CELL
4.7 μ F
BATT
LX
MAX1586
MAX1587
NiMH
RECHARGEABLE
BACKUP BATTERY
MAX1724
EZK30
SHDN
OUT
GND
3.0V
BKBT
V7
10 μ F
1 μ F
Figure 10. A 1-cell NiMH battery can provide backup by boost-
ing with a low-power DC-DC converter. A series resistor-diode
trickle charges the battery when the main power is on.
28
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相关代理商/技术参数
参数描述
MAX1587AEVKIT 功能描述:直流/直流开关转换器 MAX1587A Evaluation Kit/Evaluation System RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT
MAX1587AEVSYS 功能描述:直流/直流开关转换器 High-Efficiency Low-IQ PMICs with Dynamic Core for PDAs and Smartphones RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT
MAX1587CETL 功能描述:直流/直流开关调节器 PMICs w/Dynamic Core for PDAs RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5
MAX1587CETL+ 功能描述:直流/直流开关调节器 PMICs w/Dynamic Core for PDAs RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5
MAX1587CETL+T 功能描述:直流/直流开关调节器 PMICs w/Dynamic Core for PDAs RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5