19-0777; Rev 5; 2/10
KIT
ATION
EVALU
BLE
AVAILA
600mA/650mA PWM Step-Down Converters in
2mm x 2mm WLP for WCDMA PA Power
General Description
The MAX8805W/MAX8805X/MAX8805Y/MAX8805Z
high-frequency step-down converters are optimized for
dynamically powering the power amplifier (PA) in
WCDMA or NCDMA handsets. The devices integrate a
high-efficiency PWM step-down converter for medium-
and low-power transmission, and a 60mΩ typical
bypass FET to power the PA directly from the battery
during high-power transmission. Dual 200mA low-noise,
high-PSRR low-dropout regulators (LDOs) for PA bias-
ing are also integrated.
Two switching frequency options are available (2MHz for
the MAX8805W/MAX8805Y and 4MHz for the MAX8805X/
MAX8805Z), allowing optimization for smallest solution
size or highest efficiency. Fast switching allows the use of
small ceramic 2.2µF input and output capacitors while
maintaining low ripple voltage. The feedback network is
integrated, further reducing external component count
and total solution size.
The MAX8805W/MAX8805X/MAX8805Y/MAX8805Z use
an analog input driven by an external DAC to control
the output voltage linearly for continuous PA power
adjustment. The REFIN to OUT gain is available in two
options (2V/V for the MAX8805Y/MAX8805Z and 2.5V/V
for the MAX8805W/MAX8805X). At high-duty cycle, the
MAX8805W/MAX8805X/MAX8805Y/MAX8805Z auto-
matically switch to the bypass mode, connecting the
input to the output through a low-impedance (60mΩ
typ) MOSFET. The user can also enable the bypass
mode directly through a logic-control input.
The LDOs in the MAX8805W/MAX8805X/MAX8805Y/
MAX8805Z are designed for low-noise operation
(35µV
RMS
typ). Each LDO is individually enabled
through its own logic control interface.
The MAX8805W/MAX8805X/MAX8805Y/MAX8805Z are
available in 16-bump, 2mm x 2mm WLP and UCSP
™
packages (0.7mm max height).
UCSP is a trademark of Maxim Integrated Products, Inc.
Features
o
PA Step-Down Converter
7.5µs (typ) Settling Time for 0.8V to 3.4V Output
Voltage Change
Dynamic Output Voltage Setting from 0.4V to
V
BATT
60mΩ pFET and 100% Duty Cycle for Low
Dropout
2MHz or 4MHz Switching Frequency
Low Output-Voltage Ripple
600mA (MAX8805Y/MAX8805Z) or 650mA
(MAX8805W/MAX8805X) Output Drive
Capability
2% Gain Accuracy
Tiny External Components
o
Dual Low-Noise LDOs
Low 35µV
RMS
(typ) Output Noise
High 70dB (typ) PSRR
Guaranteed 200mA Output Drive Capability
Individual ON/OFF Control
o
Low 0.1µA Shutdown Current
o
2.7V to 5.5V Supply Voltage Range
o
Thermal Shutdown
o
Tiny 2mm x 2mm x 0.7mm WLP and UCSP
Packages (4 x 4 Grid)
MAX8805W/MAX8805X/MAX8805Y/MAX8805Z
Applications
WCDMA/NCDMA Cellular Handsets
Wireless PDAs
Smartphones
Pin Configuration appears at end of data sheet.
Ordering Information
PART
MAX8805WERExy+T*
MAX8805XERExy+T*
MAX8805YERExy+T*
PIN-PACKAGE
16 UCSP
16 UCSP
16 UCSP
SWITCHING FREQUENCY
2MHz
4MHz
2MHz
REFIN TO OUT GAIN
2.5V/V
2.5V/V
2V/V
2V/V
MAX8805ZERExy+T*
16 UCSP
4MHz
+Denotes
a lead-free/RoHS-compliant package.
T = Tape and reel.
*xy
is the output voltage code (see Table 1).
Note:
All devices are specified over the -40°C to +85°C operating temperature range.
Ordering Information continued at end of data sheet.
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
600mA/650mA PWM Step-Down Converters in
2mm x 2mm WLP for WCDMA PA Power
MAX8805W/MAX8805X/MAX8805Y/MAX8805Z
ABSOLUTE MAXIMUM RATINGS
IN1A, IN1B, IN2, REFIN, EN2, REFBP to AGND ...-0.3V to +6.0V
PAA, PAB, PA_EN, HP to AGND....-0.3V to (V
IN1A
/V
IN1B
+ 0.3V)
LDO1, LDO2, EN1 to AGND ......................-0.3V to (V
IN2
+ 0.3V)
IN2 to IN1B/IN1A ...................................................-0.3V to +0.3V
PGND to AGND .....................................................-0.3V to +0.3V
LX Current ......................................................................0.7A
RMS
IN1A/IN1B and PAA/PAB Current .....................................2A
RMS
PAA and PAB Short Circuit to PGND or IN1_.............Continuous
Continuous Power Dissipation (T
A
= +70°C)
16-Bump UCSP (derate 12.5mW/°C above +70°C) ..........1W
16-Bump WLP (derate 12.5mW/°C above +70°C).............1W
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Bump Temperature (soldering, reflow) ............................+260°C
Note:
This device is constructed using a unique set of packaging techniques that impose a limit on the thermal profile the device
can be exposed to during board level solder attach and rework. This limit permits only the use of the solder profiles recom-
mended in the industry-standard specification, JEDEC 020A, paragraph 7.6, Table 3 for IR/VPR and Convection reflow.
Preheating is required. Hand or wave soldering is not allowed.
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
IN1A
= V
IN1B
= V
IN2
= V
PA_EN
= V
EN1
= V
EN2
= 3.6V, V
HP
= 0V, V
REFIN
= 0.9V (MAX8805Y/MAX8805Z), V
REFIN
= 0.72V
(MAX8805W/MAX8805X), T
A
= -40°C to +85°C. Typical values are at T
A
=+25°C, unless otherwise noted.) (Note 1)
PARAMETER
INPUT SUPPLY
Input Voltage
Input Undervoltage Threshold
Shutdown Supply Current
V
IN1A
, V
IN1B
, V
IN2
V
IN1A
, V
IN1B
, V
IN2
rising, 180mV typical hysteresis
V
PA_EN
= V
EN1
= V
EN2
= 0V
T
A
= +25°C
T
A
= +85°C
MAX8805W/MAX8805Y
MAX8805X/MAX8805Z
2.7
2.52
2.63
0.1
0.1
150
3500
5000
150
+160
°C
250
µA
5.5
2.70
4
V
V
µA
CONDITIONS
MIN
TYP
MAX
UNITS
V
PA_EN
= 0V, I
LDO1
= I
LDO2
= 0mA
No-Load Supply Current
V
EN1
= V
EN2
= 0V, I
PA
= 0mA,
switching
V
EN1
= V
EN2
= 0V, V
HP
= 3.6V
THERMAL PROTECTION
Thermal Shutdown
LOGIC CONTROL
PA_EN, EN1, EN2, HP Logic-
Input High Voltage
PA_EN, EN1, EN2, HP Logic-
Input Low Voltage
Logic-Input Current
(PA_EN, EN1, EN2, HP)
REFIN
REFIN Common-Mode Range
MAX8805Y/MAX8805Z
MAX8805W/MAX8805X
V
REFIN
= 0.4V, 0.9V, 1.7V,
2.2V (I
LX
= 0mA)
V
REFIN
= 0.32V, 0.75V,
1.32V, 1.76V (I
LX
= 0mA)
MAX8805Y/MAX8805Z
MAX8805W/MAX8805X
MAX8805Y/MAX8805Z
MAX8805W/MAX8805X
0.1
0.1
1.96
2.45
2.7V
≤
V
IN1A
= V
IN1B
= V
IN2
≤
5.5V
2.7V
≤
V
IN1A
= V
IN1B
= V
IN2
≤
5.5V
V
IL
= 0V or V
IH
= V
IN1A
= 5.5V
T
A
= +25°C
T
A
= +85°C
1.4
T
A
rising, 20°C typical hysteresis
V
0.4
0.01
0.1
2.2
1.76
2.00
2.50
540
320
2.04
V/V
2.55
kΩ
1
V
µA
V
REFIN to PA_ Gain
REFIN Input Resistance
2
_______________________________________________________________________________________
600mA/650mA PWM Step-Down Converters in
2mm x 2mm WLP for WCDMA PA Power
ELECTRICAL CHARACTERISTICS (continued)
(V
IN1A
= V
IN1B
= V
IN2
= V
PA_EN
= V
EN1
= V
EN2
= 3.6V, V
HP
= 0V, V
REFIN
= 0.9V (MAX8805Y/MAX8805Z), V
REFIN
= 0.72V
(MAX8805W/MAX8805X), T
A
= -40°C to +85°C. Typical values are at T
A
=+25°C, unless otherwise noted.) (Note 1)
PARAMETER
REFIN
Dual Mode™ Threshold
LX
On-Resistance
LX Leakage Current
Peak Current Limit
(p-Channel MOSFET)
Valley Current Limit
(n-Channel MOSFET)
Minimum On- and Off-Times
Power-Up Delay
BYPASS
On-Resistance
Bypass Current Limit
p-channel MOSFET bypass,
I
OUT
= -90mA
V
PA
_ = 0V
MAX8805Y/MAX8805Z
MAX8805W/MAX8805X
MAX8805Y/MAX8805Z
MAX8805W/MAX8805X
T
A
= +25°C
T
A
= +85°C
MAX8805_E_EAA+T
MAX8805_E_EBC+T
Output Voltage V
LDO1
V
IN2
= 5.5V, I
LDO1
= 1mA;
V
IN2
= 3.4V, I
LDO1
= 100mA
MAX8805_E_ECC+T
MAX8805_E_EDD+T
MAX8805_E_EEE+T
MAX8805_E_EGG+T
Output Current
Current Limit
Dropout Voltage
Line Regulation
Load Regulation
Power-Supply Rejection
V
LDO1
= 0V
I
LDO1
= 100mA, T
A
= +25°C (V
LDO1
≥
2.5V)
V
IN2
stepped from 3.5V to 5.5V, I
LDO1
= 100mA
I
LDO1
stepped from 50µA to 200mA
10Hz to 10kHz, C
LDO1
= 1µF, I
LDO1
= 30mA
1.746
2.425
2.619
2.716
2.765
2.910
200
250
550
70
2.4
25
70
750
200
T
A
= +25°C
T
A
= +85°C
0.8
0.7
0.75
1.5
1.55
0.060
0.1
1.2
0.9
0.95
2.1
2.15
0.01
1
1.8
2.5
2.7
2.8
2.85
3.0
1.854
2.575
2.781
2.884
2.936
3.090
mA
mA
mV
mV
mV
dB
V
1.8
1.1
1.15
2.9
2.95
10
0.1
Ω
A
A
A
µA
p-channel MOSFET switch, I
LX
= -40mA
n-channel MOSFET rectifier, I
LX
= 40mA
V
IN1A
= V
IN1B
= V
IN2
= 5.5V,
V
LX
= 0V
V
LX
= 0V
MAX8805Y/MAX8805Z
MAX8805W/MAX8805X
MAX8805Y/MAX8805Z
MAX8805W/MAX8805X
From PA_EN rising to LX rising
T
A
= +25°C
T
A
= +85°C
MAX8805Y/MAX8805Z
MAX8805W/MAX8805X
0.7
0.75
0.5
0.55
0.18
0.15
0.1
1
0.9
0.95
0.7
0.75
0.1
0.07
150
250
1.1
1.15
0.9
0.95
0.6
0.6
5
Ω
µA
A
A
µs
µs
CONDITIONS
MAX8805Y/MAX8805Z
V
REFIN
rising, 50mV hysteresis
MAX8805W/MAX8805X
MIN
0.44 x
V
IN2
0.36 x
V
IN2
TYP
0.465 x
V
IN2
0.372 x
V
IN2
MAX
0.48 x
V
IN2
0.39 x
V
IN2
UNITS
MAX8805W/MAX8805X/MAX8805Y/MAX8805Z
V
Step-Down Current Limit in Bypass V
LX
= 0V
Total Bypass Current Limit
Bypass Off-Leakage Current
LDO1
V
LX
= V
PA
_ = 0V
V
IN1A
= V
IN1B
= V
IN2
= 5.5V,
V
PAA
= V
PAB
= 0V
Dual Mode is a trademark of Maxim Integrated Products, Inc.
_______________________________________________________________________________________
3
600mA/650mA PWM Step-Down Converters in
2mm x 2mm WLP for WCDMA PA Power
MAX8805W/MAX8805X/MAX8805Y/MAX8805Z
ELECTRICAL CHARACTERISTICS (continued)
(V
IN1A
= V
IN1B
= V
IN2
= V
PA_EN
= V
EN1
= V
EN2
= 3.6V, V
HP
= 0V, V
REFIN
= 0.9V (MAX8805Y/MAX8805Z), V
REFIN
= 0.72V
(MAX8805W/MAX8805X), T
A
= -40°C to +85°C. Typical values are at T
A
=+25°C, unless otherwise noted.) (Note 1)
PARAMETER
Output Noise
Output Capacitor for Stable
Operation
Shutdown Output Impedance
LDO2
MAX8805_E_EAA+T
MAX8805_E_EAC+T
Output Voltage V
LDO2
V
IN2
= 5.5V, I
LDO2
= 1mA;
V
IN2
= 3.4V, I
LDO2
= 100mA
MAX8805_E_EAD+T
MAX8805_E_EBE+T
MAX8805_E_EGG+T
Output Current
Current Limit
Dropout Voltage
Line Regulation
Load Regulation
Power-Supply Rejection
∆V
LDO2
/
∆V
IN2
Output Noise
Output Capacitor for Stable
Operation
Shutdown Output Impedance
REFBP
REFBP Output Voltage
REFBP Supply Rejection
0
≤
I
REFBP
≤
1µA
V
IN2
stepped from 2.55V to 5.5V
1.237
1.250
0.2
1.263
5
V
mV
V
LDO2
= 0V
I
LDO2
= 100mA, T
A
= +25°C
V
IN2
stepped from 3.5V to 5.5V, I
LDO2
= 100mA
I
LDO2
stepped from 50µA to 200mA
10Hz to 10kHz, C
LDO2
= 1µF, I
LDO2
= 30mA
100Hz to 100kHz, C
LDO2
= 1µF, I
LDO2
= 30mA
0µA < I
LDO2
< 10mA
0µA < I
LDO2
< 200mA
V
EN2
= 0V
1.746
2.619
2.716
2.765
2.910
200
250
550
70
2.4
25
70
35
100
1
1
750
200
1.8
2.7
2.8
2.85
3.0
1.854
2.781
2.884
2.936
3.090
mA
mA
mV
mV
mV
dB
µV
RMS
nF
µF
kΩ
V
0 < I
LDO1
< 10mA
0 < I
LDO1
< 200mA
V
EN1
= 0V
CONDITIONS
100Hz to 100kHz, C
LDO1
= 1µF, I
LDO1
= 30mA
MIN
TYP
35
100
1
1
MAX
UNITS
µV
RMS
nF
µF
kΩ
Note 1:
All devices are 100% production tested at T
A
= +25°C. Limits over the operating temperature range are guaranteed by design.
4
_______________________________________________________________________________________
600mA/650mA PWM Step-Down Converters in
2mm x 2mm WLP for WCDMA PA Power
Typical Operating Characteristics
(V
IN1A
= V
IN1B
= V
IN2
= 3.6V, V
PA_
= 1.2V, V
LDO1
= 2.85V, V
LDO2
= 2.85V, R
PA
= 7.5Ω, circuit of Figure 5, T
A
= +25°C, unless oth-
erwise noted.)
BYPASS MODE DROPOUT VOLTAGE
vs. PA LOAD CURRENT
BYPASS MODE DROPOUT VOLTAGE (mV)
MAX8805W/X/Y/Z toc01
MAX8805W/MAX8805X/MAX8805Y/MAX8805Z
PA STEP-DOWN CONVERTER EFFICIENCY
vs. OUTPUT VOLTAGE (MAX8805X/MAX8805Z)
MAX8805W/X/Y/Z toc02
PA STEP-DOWN CONVERTER EFFICIENCY
vs. OUTPUT VOLTAGE (MAX8805W/MAX8805Y)
MAX8805W/X/Y/Z toc03
140
120
V
IN1
= 3.2V
100
80
60
40
20
V
IN1
= 3.6V
100
100
90
EFFICIENCY (%)
BYPASS MODE
V
IN1
= 4.2V
90
EFFICIENCY (%)
BYPASS MODE
V
IN1
= 4.2V
80
V
IN1
= 3.6V
V
IN1
= 3.2V
80
V
IN1
= 3.6V
V
IN1
= 3.2V
70
R
PA
= 7.5Ω
70
R
PA
= 7.5Ω
60
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
OUTPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
0
0
0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8
PA LOAD CURRENT (A)
60
PA STEP-DOWN CONVERTER EFFICIENCY
vs. OUTPUT VOLTAGE (MAX8805X/MAX8805Z)
MAX8805W/X/Y/Z toc04
PA STEP-DOWN CONVERTER EFFICIENCY
vs. OUTPUT VOLTAGE (MAX8805W/MAX8805Y)
MAX8805W/X/Y/Z toc05
PA STEP-DOWN CONVERTER EFFICIENCY
vs. LOAD CURRENT (MAX8805X/MAX8805Z)
V
PA_
= 1.8V
90
EFFICIENCY (%)
MAX8805W/X/Y/Z toc06
100
100
100
90
EFFICIENCY (%)
BYPASS MODE
V
IN1
= 4.2V
90
EFFICIENCY (%)
BYPASS MODE
V
IN1
= 4.2V
80
V
IN1
= 3.6V
V
IN1
= 3.2V
80
V
IN1
= 3.6V
V
IN1
= 3.2V
80
V
IN1
= 3.2V
V
IN1
= 3.6V
V
IN1
= 4.2V
70
70
R
PA
= 10Ω
60
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
OUTPUT VOLTAGE (V)
70
60
R
PA
= 10Ω
60
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
OUTPUT VOLTAGE (V)
50
0
100
200
300
400
500
600
700
LOAD CURRENT (mA)
PA STEP-DOWN CONVERTER EFFICIENCY
vs. LOAD CURRENT (MAX8805W/MAX8805Y)
MAX8805W/X/Y/Z toc07
PA STEP-DOWN CONVERTER EFFICIENCY
vs. LOAD CURRENT (MAX8805X/MAX8805Z)
MAX8805W/X/Y/Z toc08
PA STEP-DOWN CONVERTER EFFICIENCY
vs. LOAD CURRENT (MAX8805W/MAX8805Y)
V
PA_
= 1.2V
MAX8805W/X/Y/Z toc09
100
V
PA_
= 1.8V
100
V
PA_
= 1.2V
90
EFFICIENCY (%)
100
90
EFFICIENCY (%)
V
IN1
= 3.2V
V
IN1
= 4.2V
90
EFFICIENCY (%)
80
80
V
IN1
= 4.2V
V
IN1
= 3.2V
V
IN1
= 3.6V
80
V
IN1
= 4.2V
70
V
IN1
= 3.2V
V
IN1
= 3.6V
V
IN1
= 3.6V
70
70
60
60
60
50
0
100
200
300
400
500
600
700
LOAD CURRENT (mA)
50
0
100
200
300
400
500
600
700
LOAD CURRENT (mA)
50
0
100
200
300
400
500
600
700
LOAD CURRENT (mA)
_______________________________________________________________________________________
5
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