MAX1935ETA15+T [ROCHESTER]
FIXED/ADJUSTABLE POSITIVE LDO REGULATOR, 0.4V DROPOUT, PDSO6, 3 X 3 MM, 0.80 MM PITCH, THIN, DUAL, QFN-6;
| 型号： | MAX1935ETA15+T |
| 厂家： | 
Rochester Electronics |
| 描述： | FIXED/ADJUSTABLE POSITIVE LDO REGULATOR, 0.4V DROPOUT, PDSO6, 3 X 3 MM, 0.80 MM PITCH, THIN, DUAL, QFN-6 光电二极管 |
| 文件： | 总11页 (文件大小：926K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-2599; Rev 0; 10/02
500mA, Low-Voltage Linear Regulator
in Tiny QFN
General Description
Features
The MAX1935 low-dropout linear regulator operates
from a 2.25V to 5.5V supply and delivers a guaranteed
500mA load current with low 175mV dropout. The high-
accuracy ( 1.5ꢀ% output voltage is preset at an inter-
nally trimmed voltage or can be adjusted from 0.8V to
4.5V with an external resistive-divider.
o Guaranteed 500mA Output Current
o Output Down to 0.8V
o Low 175mV Dropout at 500mA
o
1.5ꢀ Output Voꢁtaꢂe Aꢃꢃuraꢃc
Preset at 1.5V
An internal PMOS pass transistor allows low 210µA
supply current, making this device ideal for portable
equipment such as personal digital assistants (PDAs%,
cellular phones, cordless phones, and other equip-
ment, including base stations and docking stations.
Adjustabꢁe from 0.8V to 4.5V
o Power-OK Output
o Low 210µA Ground Current
o 0.02µA Shutdown Current
o Thermaꢁ-Overꢁoad Proteꢃtion
o Output Current Limit
Other features include an active-low, power-OK output
that indicates when the output is out of regulation, a
0.02µA shutdown mode, short-circuit protection, and
thermal-shutdown protection. The MAX1935 comes in a
tiny 1.9W, 8-pin 3mm x 3mm thin QFN package.
o Tinc 1.9W, 8-Pin 3mm x 3mm Thin QFN Paꢃkaꢂe
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
Applications
8 Thin QFN
3mm x 3mm
MAX1935ETA*
-40°C to +85°C
Notebook Computers
Cellular and Cordless Telephones
PDAs
8 Thin QFN
3mm x 3mm
MAX1935ETA15*
-40°C to +85°C
*Contact factory for preset output voltages.
Palmtop Computers
Base Stations
Selector Guide
USB Hubs
OUTPUT
VOLTAGE
Docking Stations
PART
TOP MARK
MAX1935ETA
Adjustable
1.5V
ADB
ADB
MAX1935ETA15
Typical Operating Circuit
Pin Configuration
R
TOP VIEW
POK
100kΩ
V
OUT
0.8V TO 4.5V
POK
IN
OUT
SET
TO µC
C
OUT
10µF
IN
IN
1
2
3
4
8
7
6
5
OUT
OUT
SET
R
1
V
IN
MAX1935
MAX1935
2.25V TO 5.5V
POK
SHDN
GND
C
IN
1µF
R
2
THIN QFN
3mm x 3mm
ON
GND
SHDN
OFF
________________________________________________________________ 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.
500mA, Low-Voltage Linear Regulator
in Tiny QFN
ABSOLUTE MAXIMUM RATINGS
Operating Temperature.......................................-40°C to +85°C
IN, SHDN, POK, SET to GND ...................................-0.3V to +6V
Junction Temperature......................................................+150°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10s% .................................+300°C
OUT to GND ................................................-0.3V to (V + 0.3V%
IN
Output Short-Circuit Duration.....................................Continuous
Continuous Power Dissipation (T = +70°C%
A
8-Pin Thin QFN (derate 24.4mW/°C above +70°C% .......1.95W
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 = V
+ 500mV or V = 2.25V whichever is greater, SET = GND, SHDN = IN, T = 0°C to +85°C, unless otherwise
IN
OUT(SETPOINT%
IN
A
noted. Typical values are at T = +25°C.%
A
PARAMETER
Input Voltage
SYMBOL
CONDITIONS
MIN
2.25
1.85
-1.5
-2.5
TYP
MAX
5.50
2.15
+1.5
+2.5
UNITS
V
V
V
IN
Input Undervoltage Lockout
V
Rising, 40mV hysteresis
2
UVLO
T
T
= +25°C, I
= +25°C, I
= 100mA
A
A
OUT
OUT
= 1mA to 500mA
Output Voltage Accuracy
(Preset Mode)
V
%
V
OUT
T
V
= 0°C to +85°C, I
= 1mA to 500mA,
A
OUT
-3
+3
> V
+ 0.5V
IN
OUT
Adjustable Output Voltage
0.8
788
780
4.5
812
820
T
T
T
= +25°C, I
= +25°C, I
= 100mA
A
A
OUT
= 1mA to 500mA
SET Voltage Threshold
(Adjustable Mode)
OUT
V
mV
SET
= 0°C to +85°C, I
= 1mA to 500mA,
A
OUT
774
800
826
V
V
V
> V
+ 0.5V
IN
OUT
Maximum Output Current
Short-Circuit Current Limit
SET Dual Mode™ Threshold
SET Input Bias Current
I
500
600
35
mA
RMS
OUT
I
= 0V
1400
80
2300
125
mA
LIM
OUT
mV
nA
I
= 0.8V
= 1mA
-100
+100
600
SET
SET
OUT
OUT
I
I
210
575
259
201
147
0
Ground-Pin Current
I
µA
Q
= 500mA
V
V
V
= 2.25V
= 2.8V
= 4V
400
350
275
0.125
35
OUT
OUT
OUT
Dropout Voltage (Note 1)
I
= 500mA
mV
OUT
Line Regulation
∆V
∆V
V
from (V
+ 100mV) to 5.5V, I = 5mA
LOAD
%/V
LNR
LDR
IN
OUT
Load Regulation
I
= 1mA to 500mA
15.5
300
ppm/mA
OUT
Output Voltage Noise
SHUTDOWN
10Hz to 1MHz, C
= 10µF (ESR < 0.1Ω)
µV
RMS
OUT
Shutdown Supply Current
I
SH DN = GND, V = 5.5V
0.02
5
µA
V
OFF
IN
V
1.6
IH
SH DN Input Threshold
V
IL
SHDN
0.6
SH DN Input Bias Current
I
SH DN = GND or IN
10
40
100
nA
µs
Startup Time
t
C
OUT
= 10µF, time from SH DN high to POK high
START
Dual Mode is a trademark of Maxim Integrated Products, Inc.
_______________________________________________________________________________________
2
500mA, Low-Voltage Linear Regulator
in Tiny QFN
ELECTRICAL CHARACTERISTICS (continued)
(V = V
+ 500mV or V = 2.25V whichever is greater, SET = GND, SHDN = IN, T = 0°C to +85°C, unless otherwise
IN
OUT(SETPOINT)
IN
A
noted. Typical values are at T = +25°C.)
A
PARAMETER
POWER-OK
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
POK Output Low Voltage
V
Sinking 2mA
5
50
mV
V
OL
Operating Voltage Range for
Valid POK Output
Sinking 100µA
1.0
90
5.5
Output High Leakage Current
Threshold
V
= 5.5V
100
96
nA
%
POK
Rising edge, referred to V
93
OUT(NOMINAL)
THERMAL PROTECTION
Thermal-Shutdown Temperature
Thermal-Shutdown Hysteresis
T
170
20
°C
°C
SHDN
∆T
SHDN
ELECTRICAL CHARACTERISTICS
(V = V
IN
+ 500mV or V = 2.25V whichever is greater, SET = GND, SHDN = IN, T = -40°C to +85°C, unless otherwise
IN A
OUT(SETPOINT)
noted. Typical values are at T = +25°C.) (Note 2)
A
PARAMETER
Input Voltage
SYMBOL
CONDITIONS
MIN
2.25
1.85
TYP
MAX
5.50
2.15
UNITS
V
V
V
IN
Input Undervoltage Lockout
V
Rising, 40mV hysteresis
UVLO
Output Voltage Accuracy
(Preset Mode)
V
I
= 1mA to 500mA
-4
+4
4.5
834
%
V
OUT
OUT
Adjustable Output Voltage
0.8
766
SET Voltage Threshold
(Adjustable Mode)
V
I
= 1mA to 500mA
= 0V
mV
SET
OUT
Maximum Output Current
Short-Circuit Current Limit
SET Dual Mode Threshold
SET Input Bias Current
Ground-Pin Current
I
500
600
35
mA
RMS
OUT
I
V
V
2500
125
mA
LIM
OUT
mV
nA
µA
I
= 0.8V
= 1mA
-100
+100
400
SET
SET
I
I
OUT
Q
SHUTDOWN
Shutdown Supply Current
I
SH DN = GND, V = 5.5V
5
µA
V
OFF
IN
V
2.5V < V < 5.5V
1.6
IH
IN
SH DN Input Threshold
V
IL
SHDN
2.5V < V < 5.5V
IN
0.6
SH DN Input Bias Current
I
SH DN = GND or IN
100
nA
_______________________________________________________________________________________
3
500mA, Low-Voltage Linear Regulator
in Tiny QFN
ELECTRICAL CHARACTERISTICS (continued)
(V = V
IN
+ 500mV or V = 2.25V whichever is greater, SET = GND, SHDN = IN, T = -40°C to +85°C, unless otherwise
IN A
OUT(SETPOINT)
noted. Typical values are at T = +25°C.) (Note 2)
A
PARAMETER
POWER-OK
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
POK Output Low Voltage
V
Sinking 2mA
50
mV
V
OL
Operating Voltage Range for
Valid POK Output
Sinking 100µA
1.0
89
5.5
Output High Leakage Current
Threshold
V
= 5.5V
100
97
nA
%
POK
Rising edge, referred to V
OUT(NOMINAL)
Note 1: Dropout voltage is defined as V - V
, when V
is 100mV below the value of V
and when V = V
+ 0.5V.
IN
OUT
OUT
OUT
IN
OUT(NOM)
For 2.25V ≤ V
≤ 4V, dropout voltage limits are linearly interpolated from the values listed. For V
< 4V, dropout
OUT
OUT
voltage limit is equal to the value for V
= 4V.
OUT
Note 2: Specifications to -40°C are guaranteed by design, not production tested.
Typical Operating Characteristics
(V
= 3.3V, V = V
+ 500mV, SHDN = IN, C = 1µF, C
= 10µF, T = +25°C, unless otherwise noted.)
OUT A
OUT
IN
OUT
IN
OUTPUT VOLTAGE vs. INPUT VOLTAGE
OUTPUT VOLTAGE vs. LOAD CURRENT
OUTPUT VOLTAGE vs. TEMPERATURE
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
3.32
3.31
3.30
3.29
3.28
3.27
3.26
3.25
3.34
3.33
3.32
3.31
3.30
3.29
3.28
V
OUT
= V
+ 500mV
OUT
IN
I
= 0mA
OUT
I
= 0
I
= 500mA
OUT
1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0
INPUT VOLTAGE (V)
0
100 200 300 400 500 600 700 800
LOAD CURRENT (mA)
-40
-15
10
35
60
85
TEMPERATURE (°C)
GROUND-PIN CURRENT
vs. INPUT VOLTAGE
DROPOUT VOLTAGE
vs. OUTPUT VOLTAGE
DROPOUT VOLTAGE vs. LOAD CURRENT
400
350
300
250
200
150
100
50
600
550
500
450
400
350
300
250
200
150
100
50
0.28
0.26
0.24
0.22
0.20
0.18
0.16
0.14
I
= 500mA
OUT
T
= +85°C
A
T
= +25°C
A
I
= 0mA
OUT
T
= -40°C
A
0
0
2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0
INPUT VOLTAGE (V)
2.0
2.5
3.0
3.5
4.0
4.5
0
100 200 300 400 500 600 700 800
LOAD CURRENT (mA)
OUTPUT VOLTAGE (V)
4
_______________________________________________________________________________________
500mA, Low-Voltage Linear Regulator
in Tiny QFN
Typical Operating Characteristics (continued)
(V
= 3.3V, V = V
+ 500mV, SHDN = IN, C = 1µF, C
= 10µF, T = +25°C, unless otherwise noted.)
OUT A
OUT
IN
OUT
IN
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
GROUND-PIN CURRENT
vs. LOAD CURRENT
GROUND-PIN CURRENT
vs. TEMPERATURE
500
450
400
350
300
250
200
150
100
-60
-50
-40
200
190
180
170
160
150
V
OUT
= V
+ 500mV
OUT
IN
I
= 0
V
= 5.5V
IN
V
= 3.8V
IN
-30
-20
-10
0
C
OUT
= 10µF
OUT
= 50mA
I
0.01
0.1
1
10
100
1000
-40
-15
10
35
60
85
0
100 200 300 400 500 600 700 800
LOAD CURRENT (mA)
FREQUENCY (kHz)
TEMPERATURE (°C)
OUTPUT SPECTRAL NOISE DENSITY
vs. FREQUENCY
OUTPUT NOISE DC TO 1MHz
MAX1935 toc11
10
1
C
= 10µF
OUT
= 50mA
I
OUT
V
OUT
1mV/div
0.1
0.01
V
R
= 3.3V
= 66Ω (50mA)
OUT
OUT
0.001
20ms/div
0.1
1
10
100
1000
FREQUENCY (kHz)
REGION OF STABLE C
ESR
OUT
LOAD-TRANSIENT RESPONSE
vs. LOAD CURRENT
MAX1935 toc13
100
10
I
OUT
200mA/div
C
= 10µF
OUT
1
V
OUT
20mV/div
STABLE REGION
0.1
0.01
V
= V
+ 500mV
OUT
IN
C
IN
= 10µF
R
= 660Ω TO 6.6Ω (5mA TO 500mA)
OUT
0
100 200 300 400 500 600 700 800
FREQUENCY (kHz)
10µs/div
_______________________________________________________________________________________
5
500mA, Low-Voltage Linear Regulator
in Tiny QFN
Typical Operating Characteristics (continued)
(V
= 3.3V, V = V
+ 500mV, SHDN = IN, C = 1µF, C
= 10µF, T = +25°C, unless otherwise noted.)
OUT A
OUT
IN
OUT
IN
LOAD-TRANSIENT RESPONSE
NEAR DROPOUT
LINE-TRANSIENT RESPONSE
MAX1935 toc15
MAX1935 toc14
6V
V
IN
1V/div
I
OUT
200mA/div
3V
V
OUT
50mV/div
V
= V
+ 100mV
OUT
IN
V
OUT
10mV/div
C
IN
= 10µF
R
= 660Ω TO
OUT
6.6Ω (5mA TO 500mA)
200µs/div
10µs/div
SHUTDOWN WAVEFORM
POK WAVEFORM
MAX1935 toc16
MAX1935 toc17
5V
2V
V
V
SHDN
1V/div
IN
2V/div
0
0
V
OUT
2V/div
3V
0
V
OUT
1V/div
V
POK
2V/div
0
0
R
= 6.6Ω (500mA)
R
= 66Ω (50mA)
OUT
OUT
20µs/div
200µs/div
Pin Description
PIN
1, 2
NAME
FUNCTION
Regulator Input. Supply voltage can range from 2.25V to 5.5V. Bypass with a 1µF capacitor to GND (see
the Capacitor Selection and Regulation Stability section). Connect both input pins together externally.
IN
Open-Drain, Active-Low Power-OK Output. POK remains low while the output voltage (V
POK threshold. Connect a 100kΩ pullup resistor from POK to OUT.
) is below the
OUT
3
4
POK
SHDN
GND
SET
Active-Low Shutdown Input. A logic low at SHDN reduces supply current to 0.02µA. In shutdown, the POK
output is low. Connect SHDN to IN for normal operation.
Ground. This pin and the exposed pad also function as a heatsink. Solder both to a large pad or to the
circuit-board ground plane to maximize power dissipation.
5
Voltage-Setting Input. Connect SET to GND for preset output. Connect an external resistive voltage-divider
from OUT to SET to set the output voltage between 0.8V and 4.5V. The SET regulation voltage is 800mV.
6
Regulator Output. OUT sources up to 500mA. Bypass OUT with a 10µF low-ESR capacitor to GND.
Connect both OUT pins together externally.
7, 8
OUT
6
_______________________________________________________________________________________
500mA, Low-Voltage Linear Regulator
in Tiny QFN
low. The capacitance and load at OUT determine the
Detailed Description
rate at which V
decays. SHDN can be pulled as
OUT
The MAX1935 is a low-dropout, low-quiescent-current
linear regulator. The device supplies loads up to
500mA and is available with preset output voltages. As
illustrated in Figure 1, the MAX1935 includes a 0.8V ref-
erence, error amplifier, P-channel pass transistor, and
internal feedback voltage-divider.
high as 6V, regardless of the input and output voltage.
Power-OK Output
The POK output pulls low when OUT is less than 93% of
the nominal regulation voltage. Once OUT exceeds
93% of the nominal voltage, POK goes high imped-
ance. POK is an open-drain N-channel output. To
obtain a logic voltage output, connect a pullup resistor
from POK to OUT. A 100kΩ resistor works well for most
applications. POK can be used to signal a microcon-
troller (µC), or drive an external LED to indicate power
failure. When the MAX1935 is shutdown, POK is held
low independent of the output voltage. If unused, leave
POK grounded or unconnected.
The reference is connected to the error amplifier, which
compares it with the feedback voltage and amplifies
the difference. If the feedback voltage is lower than the
reference voltage, the pass-transistor gate is pulled
lower, which allows more current to pass to the output
increasing the output voltage. If the feedback voltage is
too high, the pass-transistor gate is pulled up, allowing
less current to pass to the output.
The output voltage is fed back through either an internal
resistive voltage-divider connected to OUT or an
external resistor network connected to SET. The dual-
Current Limit
The MAX1935 monitors and controls the pass transis-
tor’s gate voltage, limiting the output current to 1.4A
(typ). The output can be shorted to ground for an indefi-
nite period of time without damaging the part.
mode comparator examines V
and selects the feed-
SET
back path. If V
is below 35mV, the internal feedback
SET
path is used, and the output is regulated to the factory-
preset voltage. Additional blocks include an output
current limiter, thermal sensor, and shutdown logic.
Thermal-Overload Protection
Thermal-overload protection limits total power dissipa-
tion in the MAX1935. When the junction temperature
Internal P-Channel Pass Transistor
The MAX1935 features a 0.4Ω P-channel MOSFET pass
transistor. Unlike similar designs using PNP pass
transistors, P-channel MOSFETs require no base drive,
which reduces operating current. PNP-based regulators
also waste considerable current in dropout when the
pass transistor saturates, and use high base-drive
currents under large loads. The MAX1935 does not
suffer from these problems.
exceeds T = +170°C, a thermal sensor turns off the
J
pass transistor, allowing the device to cool. The thermal
sensor turns the pass transistor on again after the junc-
tion temperature cools by +20°C, resulting in a pulsed
output during continuous thermal-overload conditions.
Thermal-overload protection protects the MAX1935 in
the event of fault conditions. For continuous operation,
do not exceed the absolute maximum junction-temper-
ature rating of T = +150°C.
J
Output Voltage Selection
The MAX1935’s dual-mode operation allows operation
in either a preset voltage mode or an adjustable mode.
Connect SET to GND to select the preset output
voltage. The two-digit part number suffix identifies the
output voltage. For example, the MAX1935ETA33 has a
preset 3.3V output voltage. The output voltage can also
be adjusted by connecting a voltage-divider from OUT
to SET (Figure 2). Select R2 in the 25kΩ to 100kΩ
range. Calculate R1 with the following equation:
Operating Region and Power Dissipation
The MAX1935’s maximum power dissipation depends
on the thermal resistance of the IC package and circuit
board, the temperature difference between the die
junction and ambient air, and the rate of air flow. The
✕
power dissipated in the device is P = I
(V
-
IN
OUT
V
). The maximum allowed power dissipation is
OUT
1.95W or:
PMAX = (T
- T ) / (θ + θ
)
CA
J(MAX)
A
JC
where T - T is the temperature difference between the
J
A
R1 = R2 [(V
/ V ) - 1]
SET
OUT
MAX1935 die junction and the surrounding air, θ is
JC
where V
to 4.5V.
= 0.8V, and V
can range from 0.8V
SET
OUT
the thermal resistance from the junction to the case, and
θ
CA
is the thermal resistance from the case through the
PC board, copper traces, and other materials to the sur-
rounding air. The MAX1935 package features an
exposed thermal pad on its underside. This pad lowers
the package’s thermal resistance by providing
Shutdown
Drive SHDN low to enter shutdown. During shutdown,
the output is disconnected from the input, and supply
current drops to 0.02µA. When in shutdown, POK pulls
_______________________________________________________________________________________
7
500mA, Low-Voltage Linear Regulator
in Tiny QFN
V
IN
2.25V TO 5.5V
IN
IN
C
IN
1µF
THERMAL
SENSOR
MOSFET
PRESET MODE
DRIVER WITH
I
LIM
V
OUT
0.8V TO 3.3V
OUT
OUT
ON
SHDN
C
OUT
10µF
OFF
SHUTDOWN
LOGIC
V
REF
0.8V
ERROR
AMPLIFIER
LOGIC SUPPLY
VOLTAGE (V
)
OUT
R
POK
100kΩ
MAX1935
POK
TO
µC
SET
93% V
80mV
REF
GND
Figure 1. Functional Diagram
a direct heat conduction path from the die to the PC
board. Connect the exposed backside pad and GND to
the system ground using a large pad or ground plane,
or multiple vias to the ground plane layer.
output capacitors. The output capacitor’s (C
) ESR
OUT
affects stability and output noise. Use output capacitors
with an ESR of 0.1Ω or less to ensure stability and opti-
mum transient response. Surface-mount ceramic
capacitors have very low ESR and are commonly avail-
The MAX1935 delivers up to 0.5A(RMS) and operates
with input voltages up to 5.5V, but not simultaneously.
High output currents can only be sustained when input-
output differential is within the limits outlined.
able in values up to 10µF. Connect C and C
IN
close to the MAX1935 as possible.
as
OUT
Noise, PSRR, and Transient Response
The MAX1935 is designed to operate with low dropout
voltages and low quiescent currents, while still
maintaining good noise, transient response, and AC
rejection. See the Typical Operating Characteristics for
a plot of Power-Supply Rejection Ratio (PSRR) vs.
Frequency. When operating from noisy sources,
improved supply-noise rejection and transient response
can be achieved by increasing the values of the input
and output bypass capacitors and through passive-
filtering techniques. The MAX1935 load-transient
Applications Information
Capacitor Selection and Regulator
Stability
Connect a 1µF capacitor between IN and ground and a
10µF low equivalent series-resistance (ESR) capacitor
between OUT and ground. The input capacitor (C )
IN
lowers the source impedance of the input supply.
Reduce noise and improve load-transient response,
stability, and power-supply rejection by using larger
8
_______________________________________________________________________________________
500mA, Low-Voltage Linear Regulator
in Tiny QFN
600
T = +70°C
A
V
OUT
R1 = R2
- 1
0.8V
500
400
300
200
100
0
IN
IN
OUT
OUT
V
IN
+2.25V TO +5.5V
V
OUT
T = +85°C
A
C
C
OUT
10µF
IN
R
1
MAX1935
1µF
ON
SHDN
POK
SET
OFF
0
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
INPUT-OUTPUT VOLTAGE DIFFERENCE (V)
R
2
Figure 3. Power Operating Regions: Maximum Output Current
vs. Input-Output Voltage Difference
GND
Figure 2. Adjustable Output Using External Feedback Resistors
response graphs (see the Typical Operating
Characteristics) show two components of the output
response: a DC shift from the output impedance due to
the load current change, and the transient response. A
typical transient overshoot for a step change in the load
current from 5mA to 500mA is 40mV. Increasing the
output capacitor’s value and decreasing the ESR
attenuates the overshoot.
Input-Output (Dropout) Voltage
A regulator’s minimum input-to-output voltage differential
(dropout voltage) determines the lowest usable supply
voltage. In battery-powered systems, this determines the
useful end-of-life battery voltage. Because the MAX1806
uses a P-channel MOSFET pass transistor, its dropout
voltage is a function of drain-to-source on-resistance
(R
) multiplied by the load current (see the Typical
DS(ON)
Operating Characteristics):
✕
V
= V - V
= R
I
OUT
DROPOUT
IN
OUT
DS(ON)
Chip Information
TRANSISTOR COUNT: 949
_______________________________________________________________________________________
9
500mA, Low-Voltage Linear Regulator
in Tiny QFN
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.)
PACKAGE OUTLINE, 6, 8 & 10L,
QFN THIN (DUAL), EXPOSED PAD, 3x3x0.80 mm
21-0137
C
COMMON DIMENSIONS
SYMBOL
MIN.
0.70
2.90
2.90
0.00
0.20
MAX.
A
D
E
A1
L
0.80
3.10
3.10
0.05
0.40
k
0.25 MIN
0
A20.2 REF.
PACKAGE VARIATIONS
PKG. CODE
T633-1
N
6
D2
E2
e
JEDEC SPEC
MO229 / WEEA
MO229 / WEEC
b
[(N/2)-1] x e
1.90 REF
1.95 REF
1.50–0.10 2.30–0.10 0.95 BSC
1.50–0.10 2.30–0.10 0.65 BSC
0.40–0.05
0.30–0.05
T833-1
8
T1033-1
10
1.50–0.10 2.30–0.10 0.50 BSC MO229 / WEED-3 0.25–0.05 2.00 REF
PACKAGE OUTLINE, 6, 8 & 10L,
QFN THIN (DUAL), EXPOSED PAD, 3x3x0.80 mm
21-0137
C
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.
10 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2002 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
相关型号：
MAX1935ETA15-T
Fixed/Adjustable Positive LDO Regulator, 0.8V Min, 4.5V Max, 0.4V Dropout, CMOS, PDSO6, 3 X 3 MM, 0.80 MM PITCH, THIN, DUAL, QFN-6
MAXIM
MAX1937EEI+
Switching Controller, 500kHz Switching Freq-Max, BICMOS, PDSO28, 0.150 INCH, 0.025 INCH PITCH, MO-137, QSOP-28
MAXIM
MAX1938EEI-T
Switching Controller, 500kHz Switching Freq-Max, BICMOS, PDSO28, 0.150 INCH, 0.025 INCH PITCH, MO-137, QSOP-28
MAXIM
MAX1939EEI+
Switching Controller, 500kHz Switching Freq-Max, BICMOS, PDSO28, 0.150 INCH, 0.025 INCH PITCH, MO-137, QSOP-28
MAXIM
©2020 ICPDF网 联系我们和版权申明