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| 型号： | MAX8671XETL+T |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 35/44页 |
| 文件大小： | 0K |
| 描述： | IC PMIC W/CHARGER 40-TQFN-EP |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 2,500 |
| 功能： | 充电管理 |
| 电池化学： | 锂离子（Li-Ion）、锂聚合物（Li-Pol） |
| 电源电压： | 4.1 V ~ 6.6 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（5x5） |
| 包装： | 带卷 (TR) |
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PMIC with Integrated Charger and
Smart Power Selector for Handheld Devices
TO FIND THE MAXIMUM OUTPUT CURRENT FOR REG 3 WITH V IN = 3 . 2 V TO 5 . 3 V , V OUT = 1 . 2 V , L = 4 . 7 μ H
± 20 %, AND R L = 130 m Ω :
D = OUT OUTTAR N L =
V + I (R + R )
V IN + I OUTTAR ( R N ? R P )
1.2V + 0.425A (0.12 Ω + 0.13 Ω )
5 . 3 V + 0 . 425 A ( 0 . 12 Ω ? 0 . 23 Ω )
= 0 . 249
I LIM ? OUT
1 + ( R N + R L )
0 . 555 A ?
1 + ( 0 . 12 Ω + 0 . 13 Ω )
I OUTMAX =
V ( 1 ? D )
2 × f × L
1 ? D
2 × f × L
=
1 . 2 V ( 1 ? 0 . 249 )
2 × ( 1 . 8 × 10 6 Hz ) × ( 4 . 7 × 10 ? 6 H × 0 . 8 )
1 ? 0 . 249
2 × ( 1 . 8 × 10 6 Hz ) × ( 4 . 7 × 10 ? 6 H × 0 . 8 )
= 0 . 482 A
Figure 10. Step-Down Converter Maximum Output Current Example
R FBH FBL × ? OUT ? 1 ?
= R
Efficiency LDO ≈ OUT
Linear Regulators (REG4, REG5)
The REG4 and REG5 linear regulators have low quies-
cent current, and low output noise. Each regulator sup-
plies up to 180mA to its load. Bypass each LDO output
with a 2.2μF or greater capacitor to ground. If V4 or V5
is set to less than 1.5V, bypass the output with 3.3μF or
greater.
Each linear regulator has an independent power input
(PV4 and PV5) with an input voltage range from 1.7V to
V SYS (V SYS can be up to 5.5V). Voltages below the
input undervoltage lockout threshold (1.6V) are invalid.
The regulator inputs can be driven from an efficient
low-voltage source, such as a DC-DC output, to opti-
mize efficiency (see the following equation). Bypass
each LDO input with a 1μF or greater capacitor to
ground:
V
V IN
REG5 is intended to power the system USB transceiver
circuitry and is only active when USB power is avail-
able. REG4 is powered from the battery when power is
not available at DC or USB.
See the Enable/Disable (EN) and Sequencing section
for how to enable and disable the linear regulators.
When enabled, the linear regulators soft-start by ramp-
ing their outputs up to their target voltage in 3ms. Soft-
start limits the inrush current when the regulators are
enabled.
The MAX8671X uses external resistor-dividers to set
the LDO output voltages between 0.6V and V PV_ . Use
at least 10μA of bias current in these dividers to ensure
no change in the stability of the closed-loop system. To
set the output voltage, select a value for the resistor
connected between FB_ and AGND (R FBL ). The recom-
mended value is 60.4k Ω . Next, calculate the value of
the resistor connected from FB_ to the output (R FBH ):
? V ?
? 0 . 6 V ?
For REG4, an external 0.01μF bypass capacitor from
BP to AGND in conjunction with a 150k Ω internal resis-
tor creates a 110Hz lowpass filter for noise reduction.
BP is a high-impedance node and requires a low-leak-
age capacitor. For example, a leakage of 40nA results
in a 1% error.
VL Linear Regulator
VL is the output of a 3.3V linear regulator that powers
MAX8671X internal circuitry. VL is internally powered
from the higher of USB or DC and automatically powers
up when either of these power inputs exceeds approxi-
mately 1.5V. When the higher of the DC and USB sup-
ply is between 1.5V and 3.3V, VL operates in dropout.
VL automatically powers down when both the USB and
DC power inputs are removed. Bypass VL to AGND
with a 0.1μF capacitor.
VL remains on even when USB and/or DC are in over-
voltage or undervoltage lockout, when SYS is in under-
voltage lockout, and also during thermal faults.
VL sources up to 3mA for external loads. If VL is not
used for external loads, the MAX8671X’s USB/DC cur-
rent limit guarantees compliance with the USB 2.0 input
current specifications. If VL is used for external loads,
USB/DC currents increase and might exceed the limits
outlined in the USB 2.0 specification. For example, if the
USB to SYS current is limited to 95mA and VL is sourc-
ing 3mA, I USB is 98mA. Similarly, if the USB input is sus-
pended and VL is sourcing 3mA, I USB is 3mA.
______________________________________________________________________________________
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相关代理商/技术参数 |
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|---|---|
| MAX8672ETD+T | 功能描述:电池管理 Backup Management IC for NiMH Batteries RoHS:否 制造商:Texas Instruments 电池类型:Li-Ion 输出电压:5 V 输出电流:4.5 A 工作电源电压:3.9 V to 17 V 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:VQFN-24 封装:Reel |
| MAX8672EVKIT+ | 制造商:Maxim Integrated Products 功能描述:MAX8672 EVAL KIT - Rail/Tube |
| MAX8674EVKIT+ | 制造商:Maxim Integrated Products 功能描述:STANDARD PRODUCTS - Boxed Product (Development Kits) |
| MAX8676ELB+ | 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述: |
| MAX8676EWJ+T | 制造商:Maxim from Components Direct 功能描述:THE MAXIM MAX8676EWJ+T IS A USB HOT SWAP CONTROLLER. - Tape and Reel 制造商:Maxim 功能描述:The Maxim MAX8676EWJ+T is a USB Hot Swap Controller. |
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