MIC2807
RF PA Power Management IC
2MHz, 600mA DC/DC w/DAC Input and
Bypass Switch, Dual Low Noise
200mA/30mA LDO Regulators
General Description
The MIC2807 integrates a high performance 600mA
DC/DC converter intended for powering a power amplifier
(PA) in a mobile phone with dual low noise low dropout
(LDO) regulators for the rest of the RF section. Optimized
for low noise performance, the MIC2807 improves
efficiency in the handset without compromising quality.
The MIC2807 has a 2MHz, constant frequency pulse width
modulated (PWM) DC/DC converter designed for low
noise operation and high efficiency. The output voltage
(V
OUT
) is variable from 0.3V to the input voltage (V
IN
),
adjustable from 0.3V to 3.6V through a DAC input when
V
IN
> V
OUT
. The converter will work in a 100% duty cycle
mode to offer maximum power and efficiency in the
application. In addition to 100% duty cycle, the DC/DC
converter has a bypass mode of operation where the input
voltage node (PVIN pin) is shorted to the output voltage
node (OUT pin) through a 95mΩ switch.
The integrated dual low noise low dropout regulators are
optimized for high PSRR capability and fast turn-on times.
The constant frequency DC/DC converter along with dual
low noise LDO regulators enables a very quiet and
efficient solution for mobile applications.
The MIC2807 is a µCap design, operating with small
ceramic output capacitors and inductors for stability,
reducing required board space and component cost and it
is available in the tiny 2.5mm x 2.8mm MLF
®
package.
Data sheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.
Features
•
•
•
•
•
2.7V to 5.5V input voltage range
Stable with ceramic output capacitors
Tiny 17-pin 2.5mm x 2.8mm MLF
®
Package
Thermal shutdown protection
Current limit protection
RF PA Power Supply DC/DC Converter
•
Adjustable output power supply – DAC controlled
– V
OUT
= V
DAC
x 3
•
Bypass mode operation
– Internal 95mΩ switch between PVIN and OUT pins
– V
DAC
> 1.2V
•
Up to 600mA output current in PWM mode
•
100% duty cycle operation for maximum efficiency
•
Tiny 4.7µH, 1µF output inductor and capacitor
•
Low-noise 2MHz PWM operation
•
>90% efficiency
Dual Low Noise Low Dropout Regulators
•
High accuracy – ±2% over temperature
•
High PSRR – greater than 70dB
•
Very low output noise – 32µVrms
•
LDO1 – 200mA output current capability
•
LDO2 – 30mA output current capability
Applications
•
•
•
•
•
CDMA2000 mobile phones
UMTS/WCDMA mobile phones
Wibro modules
WiFi modules
Power amplifier modules (PAMs) with linear PAs
Typical Application
V
IN
= 4.2V
4.0 I
OUT
= 100mA
3.5
2.5
2.0
1.0
0.5
0
0.1 0.3 0.5 0.7 0.9 1.1 1.3 1.5
DAC VOLTAGE (V)
1.5
O
U
T
4.5
DC/DC Output Voltage
vs. DAC Voltage
CDMA2000/WCDMA RF Power Supply Circuit
MLF and
MicroLeadFrame
are registered trademarks of Amkor Technology, Inc.
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
February 2008
V
=
V
D
AC
x
3
3.0
Bypass Mode
M9999-022008-B
Micrel, Inc.
MIC2807
Pin Description
Pin Number
1
Pin Name
DAC
Pin Function
DAC Control Input (Analog Voltage Input). Provides control of output voltage of DC/DC converter.
The output voltage is 3x’s the DAC voltage (Ex. 0.5V
DAC
= 1.5V
OUT
) when V
IN
> V
OUT
. Bypass mode is
enabled when the DAC voltage exceeds 1.2V or V
IN
≤
V
OUT
. V
OUT
= V
DAC
x 3.
Filter capacitor for LDO1 and LDO2 internal voltage reference, connect capacitor to ground.
Signal ground of chip.
Enables the LDO2 regulator.
LDO1 and LDO2 Supply Voltage. Must be connected to PIN 15.
Output of the LDO1.
Output of the LDO2.
Drain of internal bypass switch, also serves as feedback for the internal regulator.
Power ground.
Switch: Internal power MOSFET output switches of DC/DC converter.
Supply Voltage: Requires bypass capacitor to ground.
Enables LDO1 Regulator.
Enables the DC/DC Converter.
Supply voltage for DC/DC converter control circuitry and reference voltage circuit. Must be connected
to PIN 5.
No Connect.
2
3
4
5
6
7
8, 9
10
11
12
13
14
15
16, 17
BYP
AGND
EN2
VIN
LDO1
LDO2
OUT
PGND
SW
PVIN
EN1
EN
AVIN
NC
February 2008
3
M9999-022008-B
Micrel, Inc.
MIC2807
Absolute Maximum Ratings
(1)
Supply Voltage (PV
IN
, AV
IN
, V
IN
) ............................ 0V to 6V
Output Switch Voltage (V
SW
). ...........................................6V
DAC Input Voltage (V
DAC
)....................................... 0V to V
IN
Logic Input Voltage (V
EN
, V
EN1
, V
EN2
) ..................... 0V to V
IN
Power Dissipation
(3)
...................................Internally Limited
Storage Temperature (T
s
) .........................–65°C to +150°C
ESD Rating
(4)
................................................................ ±2kV
Operating Ratings
(2)
Supply Voltage (PV
IN
, AV
IN
, V
IN
) ...................... 2.7V to 5.5V
Output Voltage (V
OUT
) ............................................ 0V to V
IN
Enable Voltage (V
EN
, V
EN1
, V
EN2
)............................ 0V to V
IN
DAC Input Voltage (V
DAC
).................................... 0.1V to V
IN
Junction Temperature (T
J
) ........................ –40°C to +125°C
Thermal Resistance
2.5x2.8mm MLF-17 (θ
JA
) ...................................70°C/W
Electrical Characteristics
(5)
DC/DC Converter
V
IN
= PV
IN
= AV
IN
= V
EN
= 3.6V; V
DAC
= 0.6V; V
EN1
= V
EN2
= 0V; L = 4.7µH; C
OUT
= 1µF; T
A
= 25°C,
bold
values indicate
–40°C< T
J
< +125°C, unless noted.
LDO1/LDO2
V
IN
= V
EN1
= V
EN2
= 3.6V; C
OUTLDO1
= 2.2µF; V
EN
= 0V; C
OUTLDO2
= 1µF; I
OUT
= 100µA; T
A
= 25°C,
bold
values indicate
–40°C< T
J
< +125°C, unless noted.
Parameter
MIC2807
Supply Voltage Range
Total Quiescent Current
Enable Pin Threshold
Enable Pin Hysteresis
Enable Pin Input Current
Under-Voltage
Lockout Threshold
UVLO Hysteresis
Shutdown Temperature
(turn-on)
2.7
V
EN
= V
EN1
= V
EN2
= 3.6V
V
DAC
= 0.6V (DC/DC: not switching)
Logic Low
Logic High
480
0.4
1.3
30
0.01
2.6
85
160
20
1
100
V
DAC
= 1.3V
V
DAC
= 0.6V (regulator on, not switching)
V
DAC
= 0.6V, I
LOAD
= 0mA
3.0V< V
IN
< 4.5, I
LOAD
= 10mA
0mA < I
OUT
< 400mA
I
SW
= -100mA, High-Side Switch
I
SW
= 100mA, Low-Side Switch
0.65
1.8
490
360
1.8
0.05
0.2
0.55
0.6
0.85
2
650
450
1.854
0.5
1
0.75
0.85
1.6
2.2
5
1
2.7
5.5
V
µA
V
V
mV
µA
V
mV
ºC
ºC
µA
%
µA
µA
V
%/V
%
Ω
Ω
A
MHz
Condition
Min
Typ
Max
Units
Shutdown Temperature
Hysteresis
Total Shutdown Current
V
EN
= V
EN1
= V
EN2
= 0V
DC/DC Converter [V
EN1
= V
EN2
= 0V]
Maximum Duty Cycle
Bypass Quiescent
Current
Quiescent Current
Output Voltage
Output Voltage
Line Regulation
Output Voltage
Load Regulation
Switch On-Resistance
Current Limit
(Peak SW Current)
Frequency
1.746
February 2008
4
M9999-022008-B
FPGA/CPLD
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