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参数资料
| 型号： | MAX8731AETI+T |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 19/32页 |
| 文件大小： | 0K |
| 描述： | IC SMBUS LVL2 BATT CHRGR 28TQFN |
| 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： | 多化学 |
| 电源电压： | 8 V ~ 26 V |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 28-WFQFN 裸露焊盘 |
| 供应商设备封装： | 28-TQFN-EP（5x5） |
| 包装： | 带卷 (TR) |
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SMBus Level 2 Battery Charger
with Remote Sense
where R Pack is the total resistance in the battery pack,
R Board is the board resistance in series with the battery
charge path, t CV0 is the constant-voltage charge time
without remote sense, and t CVRS is the constant-volt-
age charge time with remote sense.
The MAX8731A includes a safety feature, which limits
the charge voltage when FBS_ or the selector is dis-
connected. The MAX8731A guarantees that CSIN does
not regulate more than 250mV above the selected
charging voltage. This also limits the extent to which
remote sense can cancel charge-path impedance.
Input Current Measurement
Use IINP to monitor the system-input current sensed
across CSSP and CSSN. The voltage at IINP is propor-
tional to the input current by the equation:
V IINP = I INPUT x RS1 x G IINP x R8
where I INPUT is the DC current supplied by the AC
adapter, G IINP is the transconductance of IINP (3mA/V
typ), and R8 is the resistor connected between IINP
and ground. Typically, IINP has a 0 to 3.5V output volt-
age range. Leave IINP open if not used.
LDO Regulator
An integrated low-dropout (LDO) linear regulator pro-
vides a 5.4V supply derived from DCIN, and delivers over
30mA of load current. The LDO powers the gate drivers
of the n-channel MOSFETs. See the MOSFET Drivers
section. LDO has a minimum current limit of 35mA. This
allows the MAX8731A to work with 87nC of total gate
charge (both high-side and low-side MOSFETs). Bypass
LDO to PGND with a 1μF or greater ceramic capacitor.
AC Adapter Detection
The MAX8731A includes a hysteretic comparator that
detects the presence of an AC power adapter. When
ACIN is greater than 2.048V, the open-drain ACOK out-
put becomes high impedance. Connect 10k Ω pullup
resistance between LDO and ACOK. Use a resistive
voltage-divider from the adapter’s output to the ACIN
pin to set the appropriate detection threshold. Select
the resistive voltage-divider not to exceed the 6V
absolute maximum rating of ACIN.
V DD Supply
The V DD input provides power to the SMBus interface.
Connect V DD to LDO, or apply an external supply to
V DD to keep the SMBus interface active while the sup-
ply to DCIN is removed. When V DD is biased the inter-
nal registers are maintained. Bypass V DD to GND with
a 0.1μF or greater ceramic capacitor.
Operating Conditions
The MAX8731A has the following operating states:
? Adapter Present: When DCIN is greater than 7.5V,
the adapter is considered to be present. In this con-
dition, both the LDO and REF function properly and
battery charging is allowed:
a) Charging: The total MAX8731A quiescent current
when charging is 1mA (max) plus the current required
to drive the MOSFETs.
b) Not Charging: To disable charging, set either
ChargeCurrent() or ChargeVoltage() to zero. When the
adapter is present and charging is disabled, the total
adapter quiescent current is less than 1mA and the
total battery quiescent current is less than 5μA.
? Adapter Absent (Power Fail): When V CSSP is less
than V CSIN + 10mV, the MAX8731A is in the power-
fail state, since the DC-DC converter is in dropout.
The charger does not attempt to charge in the
power-fail state. Typically, this occurs when the
adapter is absent. When the adapter is absent, the
total MAX8731A quiescent battery current is less
than 1μA (max).
? V DD Undervoltage (POR): When V DD is less than
2.5V, the V DD supply is in an undervoltage state and
the internal registers are in their POR state. The
SMBus interface does not respond to commands.
When V DD rises above 2.5V, the MAX8731A is in a
power-on reset state. Charging does not occur until
the ChargeVoltage() and ChargeCurrent() com-
mands are sent. When V DD is greater than 2.5V,
SMBus registers are preserved.
The MAX8731A allows charging under the following
conditions:
1) DCIN > 7.5V, LDO > 4V, REF > 3.1V
2) V CSSP > V CSIN + 210mV (15mV falling threshold)
3) V DD > 2.5V
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相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX8731AEVKIT+ | 功能描述:电源管理IC开发工具 MAX8731A Eval Kit RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V |
| MAX8731AEVSYS | 功能描述:电池管理 Evaluation System for the MAX8731A (includes an EVKit and the Maxim SMBUSMON2 board) 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 |
| MAX8731ETI+ | 制造商:Maxim Integrated Products 功能描述:CHGR MULTI-CHEM 8A 0V TO 19.2V 28TQFN - Rail/Tube |
| MAX8731ETI+T | 制造商:Maxim Integrated Products 功能描述:CHGR MULTI-CHEM 8A 0V TO 19.2V 28TQFN - Tape and Reel |
| MAX8731EVKIT | 功能描述:电池管理 SMBus Level 2 Battery Charger with Remote Sense 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 |
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