- 您现在的位置：买卖IC网 > PDF目录383332 > MAX1697 (Maxim Integrated Products, Inc.) 60mA, SOT23 Inverting Charge Pump with Shutdown PDF资料下载
参数资料
| 型号： | MAX1697 |
| 厂商： | Maxim Integrated Products, Inc. |
| 英文描述： | 60mA, SOT23 Inverting Charge Pump with Shutdown |
| 中文描述： | 60mA、SOT23封装、反相电荷泵，带有关断 |
| 文件页数： | 8/12页 |
| 文件大小： | 222K |
| 代理商： | MAX1697 |
M
60mA, SOT23 Inverting Charge Pump
with Shutdown
8
_______________________________________________________________________________________
where the output impedance is roughly approximated
by:
1
f
C1
OSC
The first term is the effective resistance of an ideal
switched-capacitor circuit (Figures 3a and 3b), and
R
SW
is the sum of the charge pump’s internal switch
resistances (typically 4
to 5
at V
IN
= +5V). The typi-
cal output impedance is more accurately determined
from the Typical Operating Characteristics
Current Limit
The MAX1697 limits its input current upon start-up to
170mA (typ). This prevents low-current or higher output
impedance input supplies (such as alkaline cells) from
being overloaded when power is applied or when the
device awakes from shutdown.
Shutdown
The MAX1697 has a logic-controlled shutdown input.
Driving
SHDN
low places the device in a low-power
shutdown mode. The charge-pump switching halts,
supply current is reduced to 2nA, and OUT is actively
pulled to ground through a 3
resistance.
Driving
SHDN
high will restart the charge pump. The
switching frequency and capacitor values determine
how soon the device will reach 90% of the input voltage.
Thermal Shutdown
The MAX1697 has a thermal shutdown mode for addi-
tional protection against fault conditions. When the tem-
perature of the die exceeds +150°C, the internal clock
stops, suspending the device’s operation. The
MAX1697 resumes operation when the die temperature
falls 15°C. This prevents the device from rapidly oscil-
lating around the temperature trip point.
Applications Information
Capacitor Selection
The charge-pump output resistance is a function of the
ESR of C1 and C2. To maintain the lowest output resis-
tance, use capacitors with low ESR. (See Table 1 for a
list of recommended manufacturers.) Tables 2 and 3
suggest capacitor values for minimizing output resis-
tance or capacitor size.
Flying Capacitor (C1)
Increasing the flying capacitor’s value reduces the out-
put resistance. Above a certain point, increasing C1’s
capacitance has negligible effect because the output
resistance is then dominated by internal switch resis-
tance and capacitor ESR.
Output Capacitor (C2)
Increasing the output capacitor’s value reduces the
output ripple voltage. Decreasing its ESR reduces both
output resistance and ripple. Lower capacitance values
can be used with light loads if higher output ripple can
be tolerated. Use the following equation to calculate the
peak-to-peak ripple:
Input Bypass Capacitor (C3)
If necessary, bypass the incoming supply to reduce its
AC impedance and the impact of the MAX1697’s switch-
ing noise. A bypass capacitor with a value equal to that
of C1 is recommended.
V
=
I
2(f
)C2
2 I
ESR
RIPPLE
OUT
OSC
OUT
C2
+
R
2R
4ESR
ESR
OUT
SW
C1
C2
(
)
+
+
+
S1
IN
S2
S3
S4
C1
C2
V
OUT
= -(V
IN
)
Figure 2. Ideal Voltage Inverter
V+
C1
f
OSC
C2
R
L
V
OUT
Figure 3a. Switched-Capacitor Model
R
EQUIV
=
R
EQUIV
V
OUT
R
L
1
V+
f
OSC
·
C1
C2
Figure 3b. Equivalent Circuit
相关PDF资料 |
PDF描述 |
|---|---|
| MAX1697R | 60mA, SOT23 Inverting Charge Pump with Shutdown |
| MAX1697REUT-T | 60mA, SOT23 Inverting Charge Pump with Shutdown |
| MAX1697S | 60mA, SOT23 Inverting Charge Pump with Shutdown |
| MAX1697T | 60mA, SOT23 Inverting Charge Pump with Shutdown |
| MAX1697U | 60mA, SOT23 Inverting Charge Pump with Shutdown |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX16970GEEA/V+ | 制造商:Maxim Integrated Products 功能描述:AUTOMOTIVE USB PROTECTOR WITH CDP AND DCP AUTODETECT - Rail/Tube |
| MAX16970GEEA/V+T | 制造商:Maxim Integrated Products 功能描述:AUTOMOTIVE USB PROTECTOR WITH CDP AND DCP AUTODETECT - Tape and Reel |
| MAX16970GEEB/V+ | 制造商:Maxim Integrated Products 功能描述:AUTOMOTIVE USB PROTECTOR WITH CDP AND DCP AUTODETECT - Rail/Tube |
| MAX16970GEEB/V+T | 制造商:Maxim Integrated Products 功能描述:AUTOMOTIVE USB PROTECTOR WITH CDP AND DCP AUTODETECT - Tape and Reel |
| MAX16970GTEB/V+ | 制造商:Maxim Integrated Products 功能描述:AUTOMOTIVE USB PROTECTOR WITH CDP AND DCP AUTODETECT - Rail/Tube |
发布紧急采购，3分钟左右您将得到回复。