MAX5008CUB+T [MAXIM]
Fixed Positive Standard Regulator, 5VBICMOS, PDSO10, MICRO MAX PACKAGE-10;
| 型号： | MAX5008CUB+T |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Fixed Positive Standard Regulator, 5VBICMOS, PDSO10, MICRO MAX PACKAGE-10 泵 |
| 文件： | 总7页 (文件大小：225K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-2426; Rev 0; 4/02
Regulated 5V USB Charge Pump with
Programmable Current Limit
General Description
Features
The MAX5008 charge-pump regulator generates a reg-
ulated 5V output up to 125mA with a 2.95V to 5.5V input
voltage range. The device includes resistor-program-
mable overcurrent limit. The MAX5008 requires a mini-
mum number of external components for normal
operation. The high 1MHz switching frequency allows
the use of small surface-mount ceramic capacitors.
ꢀ Regulated 5V Output Up to 125mA
ꢀ Indefinite Short-Circuit Protection
ꢀ Adjustable Output Current Limit
ꢀ No Inductors Required
ꢀ 0.1µA Shutdown Current
The fault-protection circuitry limits the output current
when it exceeds the limit set by an external resistor.
The output current can range from 1mA to 150mA to
accommodate circuit requirements. A FAULT output
indicates when the device is in current limit or the out-
put is out of regulation.
ꢀ Thermal Shutdown
ꢀ Fault Output Indicates Overcurrent or Output
Voltage Out of Regulation
ꢀ 2.95V to 5.5V Input Voltage Range
ꢀ 10-Pin µMAX Package
A low-power shutdown mode reduces supply current to
less than 1µA and places the output in a high-imped-
ance state. The MAX5008 is offered in a space-saving
10-pin µMAX package that is only 1.1mm high.
Applications
Ordering Information
Flash Memory Supplies
USB Host Devices
PART
TEMP RANGE
PIN-PACKAGE
MAX5008CUB
0°C to +70°C
10 µMAX
Battery-Powered Systems
3.3V to 5V Local Conversion
Pin Configuration appears at end of data sheet.
Typical Operating Circuit
C
X
0.68 F
7
9
CXN
CXP
V
IN
8
5
2.95V TO 5.5V
IN
4.7 F
200
*
2
1
V
OUT
5V
SHDN
OUT
R
C
CS
0.4
OUT
4.7 F
47nF*
100k
MAX5008
3
RCS
FAULT
200
*
10
I
CEXT
C
OUT
EXT
6.8 F
GND
4
PGND
6
*USE IF PRECISION CURRENT LIMIT IS REQUIRED.
________________________________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
Regulated 5V USB Charge Pump with
Programmable Current Limit
ABSOLUTE MAXIMUM RATINGS
IN, SHDN, RCS, FAULT, OUT to GND .....................-0.3V to +6V
Continuous Power Dissipation (T = +70°C)
A
10-Pin µMAX.................................................................444mW
Operating Temperature Range...............................0°C to +70°C
Junction Temperature......................................................+150°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
PGND to GND..................................................................... 0.3V
CXN to GND ................................................-0.3V to (V + 0.3V)
IN
CEXT
CEXT
CXP to GND ............................................-0.3V to (V
CEXT to GND ..........................................-0.3V to (V
+ 0.3V)
+ 0.3V)
Short-Circuit Duration to GND .......................................Indefinite
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(V = SHDN = 3V, C = 4.7µF, C = 0.68µF, C
= 6.8µF, C = 4.7µF, R = 0.4 , T = 0°C to +70°C, unless otherwise noted.
OUT CS A
IN
IN
X
EXT
Typical values are at T = +25°C.)
A
PARAMETER
SYMBOL
CONDITIONS
MIN
2.95
2.95
TYP
MAX
4.25
5.50
UNITS
I
I
= 125mA
= 70mA
OUT
Input Voltage Range
(Note 1)
V
V
IN
OUT
Input Undervoltage Lockout
Threshold
Rising edge
Falling edge
2.0
2.35
100
2.6
V
mV
V
Input Undervoltage Lockout
Hysteresis
0
I
< 30mA, 2.95V < V < 5.5V
4.75
4.75
5.0
5.0
5.30
5.25
OUT
IN
Output Voltage
(Note 2)
V
OUT
0mA
0mA
I
I
100mA, 2.95V
125mA
V
IN
4.25V
OUT
OUT
Output Voltage Ripple
V
100
mV
V
RIP
V
Fault Threshold
V
4.22
100
4.50
OUT
TH
Maximum Output Current
I
V
= 5V 4%
OUT
140
0.6
1
mA
OUT
I
I
= 0, V = 4.25V
6
6
OUT
OUT
IN
No-Load Input Current
I
mA
Q
= 0, V = 3.3V
IN
SHDN Logic High
V
2.4
55
V
V
INH,SHDN
SHDN Logic Low
V
0.4
10
73
1
INL,SHDN
Shutdown Supply Current
Current-Sense Trip Level
FAULT Leakage Current
FAULT Logic Low
I
SHDN = low
0.1
60
µA
mV
µA
V
QSHDN
V
V
V
= I
x R (Note 3)
CS
CS
FAULT
OUT CS
= 5V, OUT in regulation
I
I
> I
> I
, or V
< V , I = 1mA
TH FAULT
0.4
OUT
OUT
LIMIT
OUT
2
30
16
1
ms
µs
LIMIT
FAULT Assertion Delay
(Note 4)
t
FD
V
< V
TH
OUT
FAULT Deassertion Delay (Note 5)
t
I
< I
LIMIT
and V > 4.5V
OUT
ms
MHz
FDD
OUT
Switching Frequency
0.5
1.5
V
> V , R
= 46 , from rising edge
OUT
TH LOAD
Startup Time
t
200
µs
START
of SHDN
2
_______________________________________________________________________________________
Regulated 5V USB Charge Pump with
Programmable Current Limit
ELECTRICAL CHARACTERISTICS (continued)
(V = SHDN = 3V, C = 4.7µF, C = 0.68µF, C
= 6.8µF, C
= 4.7µF, R = 0.4 , T = 0°C to +70°C, unless otherwise noted.
IN
IN
X
EXT
OUT CS A
Typical values are at T = +25°C.)
A
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
150
30
MAX
UNITS
°C
Thermal Shutdown
Junction Temperature
Thermal Shutdown Hysteresis
°C
Note 1: When the input exceeds 4.25V, the power dissipation on the chip exceeds the maximum rating if the output current is 125mA.
Note 2: The MIN/MAX limits are 100% production tested at +25°C and +70°C, and guaranteed by design at 0°C.
Note 3: I
is output current flowing from C
.
OUT
EXT
Note 4: The delay from the fault event to the assertion of FAULT. Fault delays are specified with either a current fault or a voltage
fault, but not both simultaneously.
Note 5: The delay from the removal of the fault event to the deassertion of FAULT.
Typical Operating Characteristics
(V = 3V, C = 4.7µF, C = 0.47µF, C
= 4.7µF, C
= 4.7µF, R = 0.4 , T = +25°C, unless otherwise noted.)
IN
IN
X
OUT
EXT CS A
NO-LOAD SUPPLY CURRENT
vs. SUPPLY VOLTAGE
OUTPUT VOLTAGE
vs. LOAD CURRENT
OUTPUT VOLTAGE
vs. SUPPLY VOLTAGE
2.0
5.5
5.3
5.1
4.9
4.7
6
5
4
3
2
1
0
I
= 100mA
LOAD
1.5
1.0
0.5
0
V
IN
= 5.0V
V
= 2.9V
V = 3.3V
IN
IN
4.5
1
2.5
3.0
3.5
4.0
4.5
5.0
5.5
10
100
1000
0
1
2
3
4
5
6
SUPPLY VOLTAGE (V)
LOAD CURRENT (mA)
SUPPLY VOLTAGE (V)
_______________________________________________________________________________________
3
Regulated 5V USB Charge Pump with
Programmable Current Limit
Typical Operating Characteristics (continued)
(V = 3V, C = 4.7µF, C = 0.47µF, C
= 4.7µF, C
= 4.7µF, R = 0.4 , T = +25°C, unless otherwise noted.)
IN
IN
X
OUT
EXT CS A
EFFICIENCY
vs. LOAD CURRENT
OUTPUT WAVEFORM
SHUTDOWN TIMING
MAX5008 toc05
MAX5008 toc06
100
V
IN
= 2.95V
R = 46
L
90
80
70
60
50
40
30
20
10
0
5V
V
OUT
V
IN
= 3.3V
0
5V
0
10mV/div
SHDN
1
10
100
1000
200ns/div
1ms/div
LOAD CURRENT (mA)
LINE-TRANSIENT RESPONSE
LOAD-TRANSIENT RESPONSE
MAX5008 toc07
MAX5008 toc08
I
= 100mA
LOAD
A
B
100mA
10mA
3.6V
3.1V
A
B
40 s/div
40 s/div
A: INPUT VOLTAGE: 500mV/div
B: OUTPUT VOLTAGE: AC-COUPLED, 100mV/div
A: LOAD CURRENT
B: OUTPUT VOLTAGE: AC-COUPLED, 100mV/div
4
_______________________________________________________________________________________
Regulated 5V USB Charge Pump with
Programmable Current Limit
Pin Description
PIN
1
NAME
RCS
FUNCTION
External Current-Sense Resistor. Connect a resistor from RCS to OUT to set the overcurrent
threshold. I
= 60mV / R
.
CS
LIMIT
2
OUT
Fixed 5V Output. Bypass OUT to GND with a 4.7µF capacitor.
Output Fault Indicator. FAULT is asserted when either I > I
open-drain output that is high during normal operation or during shutdown.
or V
< V . FAULT is an
TH
OUT
LIMIT
OUT
3
FAULT
GND
4
Ground Pin. Connect GND to PGND.
Shutdown Input. When SHDN = low, the device turns off. Drive SHDN high or connect to IN for
normal operation.
5
SHDN
6
7
PGND
CXN
IN
Power Ground Pin. Connect PGND to GND.
Negative Terminal of the Charge-Pump Capacitor. Connect a 0.68µF capacitor from CXN to CXP.
Input Supply, 2.95V to 5.5V. Bypass IN to GND with a 4.7µF ceramic capacitor.
Positive Terminal of the Charge-Pump Capacitor. Connect a 0.68µF capacitor from CXP to CXN.
Charge-Pump Output. Bypass CEXT to PGND with a 6.8µF capacitor.
8
9
CXP
CEXT
10
Shutdown Mode
Detailed Description
Driving SHDN low places the device in shutdown
mode, which disables the oscillator, the control logic,
and the reference. The output goes into high-imped-
ance state and drops to ground if loaded. Placing the
device in shutdown mode reduces the supply current
to less than 0.1µA. In normal operation, SHDN is driven
high or connected to IN.
The MAX5008 charge pump provides a regulated 5V
output from a 2.95V to 5.5V input. The device delivers a
maximum of 125mA load current. Designed specifically
for compact applications, a complete regulator circuit
requires a minimum number of external components.
Adjustable Current Limit
The MAX5008 has an adjustable overcurrent protec-
tion. An external current-sense resistor is connected
from RCS to OUT to set the current limit. The current
limit is defined by:
Applications Information
Capacitor Selection
The MAX5008 requires four external capacitors. Their
values depend on the required output current. Table 1
shows the capacitor values recommended for different
load currents.
I
= V / RCS
CS
LIMIT
where V is the current-sense trip level, typically 60mV.
CS
For example, I
= 150mA when RCS = 0.40 .
LIMIT
Input Voltage Range
The MAX5008 maintains a regulated 5V output with
input voltages from 2.95V to 5.5V. If the input voltage
exceeds 4.25V, limit the output current to 75mA or less.
This keeps the MAX5008 within its maximum power dis-
sipation limits.
When the output current limit is exceeded, the output
voltage falls and the device maintains the average out-
put current at I
. Upon removal of the overcurrent
LIMIT
condition, the part resumes normal operation.
FAULT Indication
< V , FAULT asserts.
OUT TH
When I
> I
or V
OUT
LIMIT
Table 1. Recommended Capacitor Values
FAULT is an open-drain output that needs to be con-
nected through a 100k (typ) pullup resistor to a logic
supply voltage.
I
C
(µF)
C
(µF)
C
(µF)
C
(µF)
OUT
OUT
IN
X
EXT
50mA
3.3
4.7
0.33
0.68
3.3
6.8
3.3
4.7
Thermal Shutdown
The MAX5008 has internal thermal shutdown circuitry,
which shuts down the device when the die temperature
exceeds +150°C. The thermal shutdown circuitry has
30°C hysteresis.
125 mA
Layout Considerations
All capacitors should be located as close to the IC as
practical. Connect GND and PGND through a short,
_______________________________________________________________________________________
5
Regulated 5V USB Charge Pump with
Programmable Current Limit
Functional Diagram
Pin Configuration
TOP VIEW
CEXT
RCS
IN
RCS
OUT
1
2
3
4
5
10 CEXT
9
8
7
6
CXP
IN
MAX5008
FAULT
GND
CXN
CXP
OUT
CXN
PGND
SWITCHES
SHDN
CONTROL
MAX
MAX5008
PGND
FAULT SHDN
GND
low-impedance trace, and connect the ground for C ,
IN
Chip Information
C
, and C
directly to PGND in a star configura-
EXT
OUT
TRANSISTOR COUNT: 2632
tion. Connect R
to C
through a short and low
EXT
CS
PROCESS: BiCMOS
impedance trace.
6
_______________________________________________________________________________________
Regulated 5V USB Charge Pump with
Programmable Current Limit
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________ 7
© 2002 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
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