National Semiconductor LM3310 Technical data
查询LM3310供应商
LM3310
Step-up PWM DC/DC Converter with Integrated Op-Amp
and Gate Pulse Modulation Switch
August 2005
LM3310 Step-up PWM DC/DC Converter with Integrated Op-Amp and Gate Pulse Modulation
Switch
General Description
The LM3310 is a step-up DC/DC converter integrated with
an Operational Amplifier and a gate pulse modulation switch.
The boost (step-up) converter is used to generate an adjustable output voltage and features a low R
for maximum efficiency. The operating frequency is selectable between 660kHz and 1.28MHz allowing for the use of
small external components. An external soft-start pin enables the user to tailor the soft-start time to a specific application and limit the inrush current. The Op-Amp is capable of
sourcing/sinking 135mA of current (typical). The gate pulse
modulation switch can operate with a VGH voltage of 5V to
30V. The LM3310 is available in a low profile 24-lead LLP
package.
internal switch
DSON
Typical Application Circuit
Features
n Boost converter with a 2A, 0.18Ω switch
n Boost output voltage adjustable up to 20V
n Operating voltage range of 2.5V to 7V
n 660kHz/1.28MHz pin selectable switching frequency
n Adjustable soft-start function
n Input undervoltage protection
n Over temperature protection
n Integrated Op-Amp
n Integrated gate pulse modulation (GPM) switch
n 24-Lead LLP package
Applications
n TFT Bias Supplies
n Portable Applications
20133331
© 2005 National Semiconductor Corporation DS201333 www.national.com
Connection Diagram
LM3310
LLP-24 (Top View)
=37˚C/W
θ
JA
20133304
Ordering Information
Order Number Spec. Package
Type
LM3310SQ LLP-24 SQA24A 1000 units/reel
LM3310SQX LLP-24 SQA24A 4500 units/reel
LM3310SQ NOPB LLP-24 SQA24A 1000 units/reel
LM3310SQX NOPB LLP-24 SQA24A 4500 units/reel
NSC Package Drawing Supplied As
tape and reel
tape and reel
tape and reel
tape and reel
Pin Descriptions
Pin Name Function
1 NC Not internally connected. Leave pin open.
2 VGHM Output of GPM circuit. This output directly drives the supply for the gate driver circuits.
3 VFLK Determines when the TFT LCD is on or off. This is controlled by the timing controller in
the LCD module.
4 VDPM VDPM pin is the enable signal for the GPM block. Pulling this pin high enables the GPM
while pulling this pin low disables it. VDPM is used for timing sequence control.
5V
6AV
7 OUT Output of the Op-Amp.
8 NEG Negative input terminal of the Op-Amp.
9 POS Positive input terminal of the Op-Amp.
10 AGND Analog ground for the step-up regulator, LDO, and Op-Amp. Connect directly to DAP and
11 NC Not internally connected. Leave pin open.
12 NC Not internally connected. Leave pin open.
DD
IN
Reference input for gate pulse modulation (GPM) circuit. The voltage at VDDis used to set
the lower VGHM voltage.
Op-Amp analog power input.
PGND beneath the device.
www.national.com 2
Pin Descriptions (Continued)
Pin Name Function
13 NC Not internally connected. Leave pin open.
14 SS Boost converter soft start pin.
15 V
16 FREQ Switching frequency select input. Connect this pin to VINfor 1.28MHz operation and
17 V
18 SW Boost power switch input. Switch connected between SW pin and PGND pin.
19 SHDN
20 FB Boost output voltage feedback input.
21 PGND Power Ground. Source connection of the step-up regulator NMOS switch and ground for
22 CE Connect capacitor from this pin to AGND.
23 RE Connect a resistor between RE and PGND.
24 VGH GPM power supply input. VGH range is 5V to 30V.
DAP Die Attach Pad. Internally connected to GND. Connect AGND and PGND pins directly to
C
IN
Boost compensation network connection. Connected to the output of the voltage error
amplifier.
AGND for 660kHz operation.
Boost converter and GPM power input.
Shutdown pin. Active low, pulling this pin low disable the LM3310.
the GPM circuit. Connect AGND and PGND directly to the DAP beneath the device.
this pad beneath the device.
Block Diagrams
LM3310
20133357
www.national.com3
Block Diagrams (Continued)
LM3310
20133359
20133358
www.national.com 4
LM3310
Absolute Maximum Ratings (Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
V
IN
SW Voltage 21V
FB Voltage V
VCVoltage (Note 2) 1.265V±0.3V
SHDN Voltage
FREQ V
AV
IN
Amplifier Inputs/Output Rail-to-Rail
VGH Voltage 31V
VGHM Voltage VGH
VFLK, VDPM, V
Voltage 7.5V
DD
CE Voltage (Note 2) 1.265 + 0.3V
7.5V
IN
7.5V
IN
12V
Power Dissipation(Note 3) Internally Limited
Lead Temperature 300˚C
Vapor Phase (60 sec.) 215˚C
Infrared (15 sec.) 220˚C
ESD Susceptibility (Note 4)
Human Body Model 2kV
Operating Conditions
Operating Junction
Temperature Range (Note 5) −40˚C to +125˚C
Storage Temperature −65˚C to +150˚C
Supply Voltage 2.5V to 7V
Maximum SW Voltage 20V
VGH Voltage Range 5V to 30V
Op-Amp Supply, AV
IN
4V to 12V
RE Voltage VGH
Maximum Junction
150˚C
Temperature
Electrical Characteristics VIN=2.5V and IL=0A
Specifications in standard type face are for TJ= 25˚C and those with boldface type apply over the full Operating Temperature Range (T
Symbol Parameter Conditions Min(Note 5) Typ(Note 6) Max(Note 5) Units
I
Q
V
FB
%V
/∆VINFeedback Voltage Line
FB
I
CL
I
B
I
SS
V
SS
V
IN
g
m
A
V
D
MAX
f
S
I
SHDN
I
L
R
DSON
Th
SHDN
UVP Undervoltage Protection
= −40˚C to +125˚C). Unless otherwise specified, VIN=2.5V and IL= 0A.
J
Quiescent Current FB = 2V (Not Switching) 690 1100
V
SHDN
=0V
0.04
0.5
8.5
660kHz Switching 2.1 2.8
1.28MHz Switching 3.1 4.0
Feedback Voltage 1.231 1.263 1.287 V
2.5V ≤ VIN≤ 7V -0.26 0.089 0.42 %/V
Regulation
Switch Current Limit (Note 7) (Note 8) 2.0 2.6 A
FB Pin Bias Current (Note 9) 27 160 nA
SS Pin Current 8.5 11 13.5 µA
SS Pin Voltage 1.20 1.24 1.28 V
Input Voltage Range 2.5 7 V
Error Amp Transconductance ∆I = 5µA 26 74 133 µmho
Error Amp Voltage Gain 69 V/V
Maximum Duty Cycle fS= 660kHz 80 91
f
= 1.28MHz 80 89
S
Switching Frequency FREQ = Ground 440 660 760 kHz
Shutdown Pin Current V
FREQ = V
SHDN
V
SHDN
IN
= 2.5V 8 13.5 µA
= 0.3V 1 2
1.0 1.28 1.5 MHz
Switch Leakage Current VSW= 20V 0.03 5 µA
Switch R
DSON
SHDN Threshold Output High, VIN= 2.5V to
ISW= 500mA 0.18 0.35 Ω
7V
Output Low, V
= 2.5V to 7V 0.4
IN
1.4
On Threshold (Switch On) 2.5 2.4
Threshold
Off Threshold (Switch Off) 2.3 2.1
µA
mA
%
V
V
www.national.com5
Electrical Characteristics VIN=2.5V and IL=0A (Continued)
Specifications in standard type face are for TJ= 25˚C and those with boldface type apply over the full Operating Tempera-
LM3310
ture Range (T
= −40˚C to +125˚C). Unless otherwise specified, VIN=2.5V and IL= 0A.
J
Symbol Parameter Conditions Min(Note 5) Typ(Note 6) Max(Note 5) Units
I
FREQ
FREQ Pin Current FREQ = VIN= 2.5V 2.7 13.5 µA
Electrical Characteristics VIN=2.5V and AVIN=8V
Specifications in standard type face are for TJ= 25˚C and those with boldface type apply over the full Operating Temperature Range (T
= −40˚C to +125˚C). Unless otherwise specified VIN=2.5V and AVIN= 8V.
J
Operational Amplifier
Symbol Parameter Conditions Min(Note 5) Typ(Note 6) Max(Note 5) Units
V
OS
I
B
V
Swing Buffer, RL=2kΩ,VOmin. 0.001 0.03
OUT
AV
IN
Is+ Supply Current Buffer, V
I
OUT
Input Offset Voltage Buffer configuration, VO=
/2, no load
AV
IN
Input Bias Current (POS Pin) Buffer configuration, VO=
/2, no load (Note 9)
AV
IN
Buffer, R
=2kΩ,VOmax. 7.9 7.97
L
5.7 15 mV
200 550 nA
Supply Voltage 412V
=AVIN/2, No Load 1.5 7.8 mA
O
Output Current Source 90 138 195
Sink 105 135 175
Electrical Characteristics VIN=2.5V
Specifications in standard type face are for TJ= 25˚C and those with boldface type apply over the full Operating Temperature Range (T
Gate Pulse Modulation
Symbol Parameter Conditions Min(Note 5) Typ(Note 6) Max(Note 5) Units
VFLK VFLK Voltage Levels Rising edge threshold 1.4
VDPM VDPM Voltage Levels Rising edge threshold 1.4
V
DD(TH)
I
VFLK
I
VDPM
I
VGH
R
VGH-VGHM
R
VGHM-RE
R
VGHM(OFF)
I
CE
V
CE(TH)
Note 1: Absolute maximum ratings are limits beyond which damage to the device may occur. Operating Ratings are conditions for which the device is intended to
be functional, but device parameter specifications may not be guaranteed. For guaranteed specifications and test conditions, see the Electrical Characteristics.
Note 2: Under normal operation the V
the pin, however the V
Note 3: The maximum allowable power dissipation is a function of the maximum junction temperature, T
and the ambient temperature, T
at any ambient temperature is calculated using: P
temperature, and the regulator will go into thermal shutdown.
Note 4: The human body model is a 100pF capacitor discharged through a 1.5kΩ resistor into each pin per JEDEC standard JESD22-A114.
= −40˚C to +125˚C). Unless otherwise specified VIN=2.5V.
J
Falling edge threshold 0.4
Falling edge threshold 0.4
VDDThreshold VGHM = 30V 2.8 3 3.3
VGHM = 5V 0.4 0.5 0.7
VFLK Current VFLK = 1.5V 4.8 11
VFLK = 0.3V 1.1 2.5
VDPM Current VDPM = 1.5V 4.8 11
VDPM = 0.3V 1.1 2.5
VGH Bias Current VGH = 30V, VFLK High 59 300
VGH = 30V, VFLK Low 11 35.5
VGH to VGHM Resistance 20mA Current, VGH = 30V 14 28.5
VGHM to RE Resistance 20mA Current, VGH = VGHM
= 30V
27 55
VGH Resistance VDPM is Low, VGHM = 2V 1.2 1.7 kΩ
CE Current CE = 0V 7 11 16 µA
CE Voltage Threshold 1.16 1.22 1.34 V
and CE pins may go to voltages above this value. The maximum rating is for the possibility of a voltage being applied to
and CE pins should never have a voltage directly applied to them.
C
C
(MAX), the junction-to-ambient thermal resistance, θJA,
. See the Electrical Characteristics table for the thermal resistance of various layouts. The maximum allowable power dissipation
A
(MAX) = (T
D
J(MAX)−TA
)/θJA. Exceeding the maximum allowable power dissipation will cause excessive die
J
V
mA
V
V
V
µA
µA
µA
Ω
www.national.com 6
Electrical Characteristics VIN=2.5V (Continued)
Note 5: All limits guaranteed at room temperature (standard typeface) and at temperature extremes (bold typeface). All room temperature limits are 100%
production tested. All limits at temperature extremes are guaranteed via correlation using standard Statistical Quality Control (SQC) methods. All limits are used to
calculate Average Outgoing Quality Level (AOQL).
Note 6: Typical numbers are at 25˚C and represent the most likely norm.
Note 7: Duty cycle affects current limit due to ramp generator.
Note 8: Current limit at 0% duty cycle. See TYPICAL PERFORMANCE section for Switch Current Limit vs. V
Note 9: Bias current flows into pin.
IN
Typical Performance Characteristics
SHDN Pin Current vs. SHDN Pin Voltage SS Pin Current vs. Input Voltage
LM3310
20133361
FREQ Pin Current vs. Input Voltage FB Pin Current vs. Temperature
20133363
20133362
20133364
www.national.com7
Typical Performance Characteristics (Continued)
LM3310
CE Pin Current vs. Input Voltage VDPM Pin Current vs. VDPM Pin Voltage
20133360
20133365
VFLK Pin Current vs. VFLK Pin Voltage 660kHz Switching Quiescent Current vs. Input Voltage
20133366
1.28MHz Switching Quiescent Current vs. Input Voltage 660kHz Switching Quiescent Current vs. Temperature
20133367
www.national.com 8
20133387
20133388
Loading...