National Semiconductor LM3200 Technical data
November 2004
LM3200
Miniature, Adjustable, Step-Down DC-DC Converter with
Bypass Mode for RF Power Amplifiers
LM3200 Miniature, Adjustable, Step-Down DC-DC Converter with Bypass Mode for RF Power
Amplifiers
General Description
The LM3200 is a DC-DC converter optimized for powering
RF power amplifiers (PAs) from a single Lithium-Ion cell. It
steps down an input voltage of 2.7V to 5.5V to a variable
output voltage of 0.8V to 3.6V. The output voltage is set
using an analog input ( V
RF PA at various power levels.
The LM3200 offers superior features and performance for
mobile phones and similar RF PA applications. Fixedfrequency PWM mode minimizes RF interference. Bypass
mode turns on an internal bypass switch to power the PA
directly from the battery. LM3200 has both forced and automatic bypass modes. Shutdown mode turns the device off
and reduces battery consumption to 0.1 µA (typ.). The
LM3200 is available in a 10-pin lead free micro SMD package. A high switching frequency (2 MHz) allows use of tiny
surface-mount components. Only three small external
surface-mount components, an inductor and two ceramic
capacitors are required.
) for optimizing efficiency of the
CON
Typical Application
Features
n 2 MHz (typ.) PWM Switching Frequency
n Operates from a single Li-Ion cell (2.7V to 5.5V)
n Variable Output Voltage (0.8V to 3.6V)
n 300 mA Maximum load capability (PWM mode)
n 500 mA Maximum load capability (Bypass mode)
n PWM, Forced and Automatic Bypass Mode
n High Efficiency (96% Typ at 3.6V
from internal synchronous rectification
n 10-pin micro SMD Package
n Current Overload Protection
n Thermal Overload Protection
, 3.2V
IN
at 120 mA)
OUT
Applications
n Cellular Phones
n Hand-Held Radios
n RF PC Cards
n Battery Powered RF Devices
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© 2004 National Semiconductor Corporation DS201261 www.national.com
Connection Diagrams
LM3200
Top View
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Bottom View
20126103
10–Bump Thin Micro SMD Package, Large Bump
See NS Package Number TLP10NHA
Order Information
Order Number Package Marking (Note) Supplied As
LM3200TL XYTT SCUB 250 Units, Tape and Reel
LM3200TLX XYTT SCUB 3000 Units, Tape and Reel
Note: The package marking “XY” designates the date code. “TT” is a NSC internal code for die traceability.
Pin Description
Pin # Name Description
A1 V
B1 V
DD
CON
C1 FB Feedback Analog Input. Connect to the output at the output filter capacitor. (Figure 1)
D1 BYP Bypass. Use this digital input to command operation in Bypass mode. Set BYP low for normal
D2 EN Enable Input. Set this digital input high after Vin
D3 PGND Power Ground
C3 SW Switching Node connection to the internal PFET switch and NFET synchronous rectifier.
B3 PV
IN
A3 BYPOUT Bypass FET Drain. Connect to the output capacitor. (Figure 1) Do not leave floating.
A2 SGND Analog and Control Ground
Analog Supply Input. A 0.1 µF ceramic capacitor is recommended to be placed as close to this
pin as possible. (Figure 1)
Voltage Control Analog input. V
CON
controls V
in PWM mode. Set: V
OUT
OUT
=3xV
CON.
leave floating.
operation.
>
2.7V for normal operation. For shutdown, set
low.
Connect to an inductor with a saturation current rating that exceeds the maximum Switch Peak
Current Limit specification of the LM3200.
Power Supply Voltage Input to the internal PFET switch and Bypass FET. (Figure 1)
Do not
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LM3200
Absolute Maximum Ratings (Notes 1, 2)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
,PVINto SGND −0.2V to +6.0V
V
DD
PGND to SGND −0.2V to +0.2V
EN, FB, BYP, V
CON
SW, BYPOUT (PGND −0.2V)
PVINto V
DD
Continuous Power Dissipation
(SGND −0.2V)
+0.2V)
to (V
DD
w/6.0V max
IN
+0.2V)
to (PV
w/6.0V max
−0.2V to +0.2V
ESD Rating (Note 4)
Human Body Model: All other pins
Human Body Model: PV
Machine Model: All pins
Operating Ratings (Notes 1, 2)
Input Voltage Range 2.7V to 5.5V
Recommended Load Current
PWM Mode 0 mA to 300 mA
Bypass Mode 0 mA to 500 mA
Junction Temperature (T
Ambient Temperature (T
(Note 5)
(Note 3) Internally Limited
Junction Temperature (T
J-MAX)
+150˚C
Storage Temperature Range −65˚C to +150˚C
Maximum Lead Temperature
(Soldering, 10 sec) +260˚C
Thermal Properties
Junction-to-Ambient Thermal 100˚C/W
Resistance (θ
), TLP10 Package (Note 6)
JA
Electrical Characteristics (Notes 2, 7) Limits in standard typeface are for T
face type apply over the full operating ambient temperature range (−25˚C ≤ T
fications apply to the LM3200 with: PV
IN=VDD
= EN = 3.6V, BYP = 0V.
≤ +85˚C). Unless otherwise noted, speci-
A=TJ
2.0 kV
pin
IN
1.0 kV
200V
) Range −25˚C to +125˚C
J
) Range
A
A=TJ
= 25˚C. Limits in bold-
−25˚C to +85˚C
Symbol Parameter Conditions Min Typ Max Units
V
IN
V
FB, MIN
V
FB, MAX
OVP Over-Voltage
V
BYPASS−
V
BYPASS+
I
SHDN
I
Q_PWM
I
Q_BYP
R
DSON (P)
R
DSON (N)
R
DSON
(BYP)
I
LIM-PFET
I
LIM-BYP
F
OSC
V
IH
Input Voltage Range
(Note 8)
Feedback Voltage at
Minimum Setting
Feedback Voltage at
Maximum Setting
Protection Threshold
Auto Bypass Detection
Negative Threshold
Auto Bypass Detection
Positive Threshold
Shutdown Supply
Current (Note 11)
DC Bias Current into
V
DD
Pin-Pin Resistance for
PFET
Pin-Pin Resistance for
N-FET
Pin-Pin Resistance for
Bypass FET
PVIN=VDD=V
V
= 0.267V, VIN= 3.6V
CON
V
= 1.20V, VIN= 4.2V
CON
(Note 9)
(Note 10)
(Note 10)
EN = SW = BYPOUT = V
V
= 0.267V, FB = 2V, No-Load 720 850 µA
CON
BYP = 3.6V, V
ISW= 500mA
ISW= - 200mA
I
BYPOUT
CON
= 500mA
IN
2.7 5.5 V
0.75 0.800 0.85 V
3.528 3.600 3.672 V
330 400 mV
160 250 320 mV
350 450 540 mV
=FB=0V
CON
0.1 3 µA
= 0V, No-Load 720 850 µA
320 450 mΩ
310 450 mΩ
85 120 mΩ
Switch Current Limit (Note 12) 700 820 940 mA
Bypass FET Current
Limit
Internal Oscillator
Frequency
Logic High Input
Threshold for EN, BYP
(Note 13)
800 1000 1200 mA
1.7 2 2.2 MHz
1.20 V
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Electrical Characteristics (Notes 2, 7) Limits in standard typeface are for T
type apply over the full operating ambient temperature range (−25˚C ≤ T
LM3200
specifications apply to the LM3200 with: PV
IN=VDD
= EN = 3.6V, BYP = 0V. (Continued)
A=TJ
≤ +85˚C). Unless otherwise noted,
= 25˚C. Limits in boldface
A=TJ
Symbol Parameter Conditions Min Typ Max Units
V
IL
I
PIN
Gain V
I
CON
Logic Low Input
Threshold for EN, BYP
Pin Pull Down Current
for EN, BYP
CON
V
CON
to V
Input Leakage
Gain 3 V/V
OUT
Current
EN, BYP = 3.6V
V
= 1.2V
CON
0.4 V
5 10 µA
10 nA
System Characteristics The following spec table entries are guaranteed by design if the component values
in the typical application circuit are used. These parameters are not guaranteed by production testing.
Symbol Parameter Conditions Min Typ Max Units
T
RESPONSE
C
CON
T
ON_BYP
T
BYP
Time for V
OUT
to Rise
from 0.8V to 3.4V in
PWM Mode
V
Input
CON
Capacitance
Bypass FET Turn On
Time In Bypass Mode
Auto Bypass Detect
Delay Time
V
R
IN
LOAD
= 4.2V, C
=15Ω
OUT
= 4.7 µF,
L = 2.2 uH
V
= 1V,
CON
Test frequency = 100 kHz
VIN= 3.6V, V
= 4.7 µF, R
C
OUT
CON
= 0.267V,
=15Ω
LOAD
BYP = Low to High
(Note 10)
25 µs
15 pF
30 µs
10 15 20 µs
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the component may occur. Operating Ratings are conditions under which operation of
the device is guaranteed. Operating Ratings do not imply guaranteed performance limits. For guaranteed performance limits and associated test conditions, see the
Electrical Characteristics tables.
Note 2: All voltages are with respect to the potential at the GND pins.
Note 3: Internal thermal shutdown circuitry protects the device from permanent damage. Thermal shutdown engages at T
130˚C (typ.).
Note 4: The Human body model is a 100 pF capacitor discharged through a 1.5 kΩ resistor into each pin. (MIL-STD-883 3015.7) The machine model is a 200 pF
capacitor discharged directly into each pin.
Note 5: In applications where high power dissipation and/or poor package thermal resistance is present, the maximum ambient temperature may have to be
de-rated. Maximum ambient temperature (T
dissipation of the device in the application (P
following equation: T
Note 6: Junction-to-ambient thermal resistance (θ
standard JESD51-7. A 1" x 1", 4 layer, 1.5 oz. Cu board was used for the measurements.
Note 7: Min and Max limits are guaranteed by design, test, or statistical analysis. Typical numbers are not guaranteed, but do represent the most likely norm.
Note 8: The LM3200 is designed for mobile phone applications where turn-on after power-up is controlled by the system controller and where requirements for a
small package size overrule increased die size for internal Under Voltage Lock-Out (UVLO) circuitry. Thus, it should be kept in shutdown by holding the EN pin low
until the input voltage exceeds 2.7V.
Note 9: Over-Voltage protection (OVP) threshold is the voltage above the nominal VOUT where the OVP comparator turns off the PFET switch while in PWM mode.
Note 10: V
switching FETs turn off. This is called the Bypass mode. Bypass mode is exited when V
The hysterisis for the bypass detection threshold V
Note 11: Shutdown current includes leakage current of PFET and Bypass FET.
Note 12: Electrical Characteristic table reflects open loop data (FB=0V and current drawn from SW pin ramped up until cycle by cycle current limit is activated).
Refer to datasheet curves for closed loop data and its variation with regards to supply voltage and temperature. Closed loop current limit is the peak inductor current
measured in the application circuit by increasing output current until output voltage drops by 10%.
Note 13: Bypass FET current limit is defined as the load current at which the FB voltage is 1V lower than V
A-MAX=TJ-MAX-OP
is compared to the programmed output voltage (V
IN
–(θJAxP
) is dependent on the maximum operating junction temperature (T
A-MAX
), and the junction-to ambient thermal resistance of the part/package in the application (θJA), as given by the
D-MAX
).
D-MAX
) is taken from thermal measurements, performed under the conditions and guidelines set forth in the JEDEC
JA
BYPASS
+
–V
). When VIN–V
OUT
− will always be positive and will be approximately 200 mV(typ.).
BYPASS
falls below V
OUT
IN–VOUT
BYPASS−
exceeds V
for longer than T
BYPASS
.
IN
= 150˚C (typ.) and disengages at TJ=
J
= 125˚C), the maximum power
J-MAX-OP
the Bypass FET turns on and the
+
BYP
for longer than T
, and PWM mode returns.
BYP
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LM3200
Typical Performance Characteristics (Circuit in Figure 1,PV
IN=VDD
= EN = 3.6V, BYP = 0V, TA=
25˚C, unless otherwise noted)
Quiescent Supply Current vs Supply Voltage Shutdown Supply Current vs Temperature
(EN = 0V)
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Switching Frequency Variation vs Temperature
(V
OUT
= 1.5V, I
OUT
= 200 mA)
Output Voltage vs Supply Voltage
(V
= 1.5V)
OUT
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Output Voltage vs Temperature
= 1.5V)
(V
OUT
20126106
20126107
Output Voltage vs Temperature
(V
= 3.25V)
OUT
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