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MAX8805Z
User Manual
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Rainbow Electronics MAX8805Z User Manual

General Description
The 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 biasing are also integrated.
Two switching frequency options are available—2MHz (MAX8805Y) and 4MHz (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 MAX8805Y/MAX8805Z use an analog input driven by an external DAC to control the output voltage linearly for continuous PA power adjustment. At high duty cycle, the MAX8805Y/MAX8805Z automatically 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 MAX8805Y/MAX8805Z are designed for low-noise operation (35µV
RMS
typ). Each LDO is indi-
vidually enabled through its own logic control interface.
The MAX8805Y/MAX8805Z are available in a 16-bump, 2mm x 2mm WLP package (0.7mm max height).
Applications
WCDMA/NCDMA Cellular Handsets
Wireless PDAs
Smartphones
Features
♦ 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 Output Drive Capability 2% Maximum Accuracy Tiny External Components
♦ Dual Low-Noise LDOs
Low 35µV
RMS
(typ) Output Noise High 70dB (typ) PSRR Guaranteed 200mA Output Drive Capability Individual ON/OFF Control
♦ Low 0.1µA Shutdown Current
♦ 2.7V to 5.5V Supply Voltage Range
♦ Thermal Shutdown
♦ Tiny 2mm x 2mm x 0.7mm WLP Package
(4 x 4 Grid)
MAX8805Y/MAX8805Z
600mA PWM Step-Down Converters in
2mm x 2mm WLP for WCDMA PA Power
________________________________________________________________
Maxim Integrated Products
1
Ordering Information
IN1A
LX
PAA
1μH
BATT
2.7V TO 5.5V
AGND
PA_EN
REFIN
EN1
EN2
IN2
BATT
2.7V TO 5.5V
PA ON/OFF
ANALOG CONTROL
V
PA
0.4V TO V
BATT
REFBP
IN1B
LDO1 ON/OFF
LDO2 ON/OFF
PAB
LDO2
LDO1
V
LDO2
UP
TO 200mA
PGND
HP
FORCED BYPASS
2.2μF
2.2μF
MAX8805Z
V
LDO1
UP
TO 200mA
Typical Operating Circuit
19-0777; Rev 0; 4/07
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.
+
Denotes a lead-free package.
T
= Tape and reel package.
*
xy is the output voltage code (see Table 1 in the Output
Voltages section).
Note: All devices are specified over the -40°C to +85°C operat­ing temperature range.
Pin Configuration appears at end of data sheet.
PART
PIN-
PKG
SWI T C H I N G
F R EQ U EN C Y
( M H z)
MAX8805YEWExy+T*
2
MAX8805ZEWExy+T*
4
PACKAGE
16 WLP-16 W162B2+ 1
16 WLP-16 W162B2+ 1
CODE
MAX8805Y/MAX8805Z
600mA PWM Step-Down Converters in 2mm x 2mm WLP for WCDMA PA Power
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(V
IN1A
= V
IN1B
= V
IN2
= V
PA_EN
= V
EN1
= V
EN2
= 3.6V, V
HP
= 0V, V
REFIN
= 0.9V, TA= -40°C to +85°C. Typical values are at TA =
+25°C, unless otherwise noted.) (Note 1)
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.
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/VIN1B
+ 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 GND or IN...................Continuous
Continuous Power Dissipation (T
A
= +70°C)
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) ............................+235°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 recom­mended 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.
Dual Mode is a trademark of Maxim Integrated Products, Inc.
INPUT SUPPLY
Input Voltage V
Input Undervoltage Threshold V
Shutdown Supply Current V
No-Load Supply Current
THERMAL PROTECTION
Thermal Shutdown TA rising, 20°C typical hysteresis +160 °C
LOGIC CONTROL
PA_EN, EN1, EN2, HP Logic­Input High Voltage
PA_EN, EN1, EN2, HP Logic­Input Low Voltage
Logic-Input Current (PA_EN, EN1, EN2, HP)
REFIN
REFIN Common-Mode Range 0.1 2.2 V
REFIN to PA_ Gain (Falling Edge) V
REFIN Input Resistance 540 kΩ
REFIN Dual Mode™ Threshold
PARAMETER CONDITIONS MIN TYP MAX UNITS
, V
, V
= V
= 0V, I
= V
IN1B
IN1B
EN2
, V
IN2
, V
rising, 180mV typical hysteresis 2.52 2.63 2.70 V
IN2
= V
EN2
= I
= 0V
LDO2
EN1
LDO1
= 0V, IPA = 0A,
IN1A
IN1A
PA_EN
V
PA_EN
V
EN1
switching
V
= V
EN1
2.7V ≤ V
2.7V ≤ V
= 0V or V
V
IL
REFIN
V
REFIN
= 0V, VHP = 3.6V 150
EN2
IN1A
IN1A
= V
= V
IH
= V
IN1B
IN1B
IN1A
= V
= V
= 5.5V
= 0.4V, 0.9V, 1.7V, 2.2V 1.96 2.00 2.04 V/V
rising, 50mV hysteresis
2.7 5.5 V
TA = +25°C 0.1 4
T
= +85°C 0.1
A
= 0A 150 250
MAX8805Y 3500
MAX8805Z 5000
≤ 5.5V 1.4 V
IN2
≤ 5.5V 0.4 V
IN2
TA = +25°C 0.01 1
T
= +85°C 0.1
A
0.45 x
0.465 x
V
IN2
V
IN2
0.48 x V
IN2
µA
µA
µA
V
MAX8805Y/MAX8805Z
600mA PWM Step-Down Converters in
2mm x 2mm WLP for WCDMA PA Power
_______________________________________________________________________________________ 3
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, TA= -40°C to +85°C. Typical values are at TA =
+25°C, unless otherwise noted.) (Note 1)
LX
On-Resistance
LX Leakage Current
p-Channel MOSFET Peak Current Limit
n-Channel MOSFET Valley Current Limit
Minimum On- and Off-Times 0.1 µs
Power-Up Delay From PA_EN rising to LX rising 150 250 µs
BYPASS
On-Resistance
Bypass Current Limit VPA = 0 0.8 1.2 1.8 A
S tep - D ow n C ur r ent Li m i t i n Byp ass VLX = 0 0.7 0.9 1.1 A
Total Bypass Current Limit VLX = VPA = 0 1.5 2.1 2.9 A
Bypass Off-Leakage Current
LDO1
Output Voltage V
Output Current 200 mA
Current Limit V
Dropout Voltage I
Line Regulation V
Load Regulation I
Power-Supply Rejection ΔV
LDO1
Output Noise 100Hz to 100kHz, C
Output Capacitor for Stable Operation
Shutdown Output Impedance V
PARAMETER CONDITIONS MIN TYP MAX UNITS
p-channel MOSFET switch, ILX = -40mA 0.18 0.6
n-channel MOSFET rectifier, I
V
= V
IN1A
= 0V
V
LX
V
= 0V 0.7 0.9 1.1 A
LX
IN1B
= V
IN2
= 5.5V,
= 40mA 0.15 0.6
LX
TA = +25°C 0.1 5
T
= +85°C 1
A
0.5 0.7 0.9 A
p-channel MOSFET bypass,
= -90mA
I
OUT
V V
IN1A
PAA
= V = V
IN1B
PAB
= V
= 0V
IN2
= 5.5V,
TA = +25°C 0.060 0.1
T
= +85°C 0.1
A
TA = +25°C 0.01 10
T
= +85°C 1
A
MAX8805YEWEAA+T 1.746 1.8 1.854
MAX8805YEWEBC+T 2.425 2.5 2.575
LDO1
V
IN2
V
IN2
= 5.5V, I = 3.4V, I
LDO1
LDO1
= 1mA; = 100mA
MAX8805YEWECC+T 2.619 2.7 2.781
MAX8805YEWEDD+T 2.716 2.8 2.884
MAX8805YEWEEE+T 2.765 2.85 2.936
/ ΔV
IN2
MAX8805YEWEGG+T 2.910 3.0
= 0V 250 550 750 mA
LDO1
= 100mA, TA = +25°C (V
LDO1
stepped from 3.5V to 5.5V, I
IN2
stepped from 50µA to 200mA 25 mV
LDO1
10Hz to 10kHz, C
0 < I
0 < I
EN1
< 10mA 100 nF
LDO1
< 200mA 1 µF
LDO1
= 0V 1 kΩ
LDO1
LDO1
= 1µF, I
= 1µF, I
≥ 2.5V) 70 200 mV
LDO1
= 100mA 2.4 mV
LDO1
= 30mA 70 dB
LDO1
= 30mA 35 µV
LDO1
3.090
Ω
µA
Ω
µA
V
RMS
MAX8805Y/MAX8805Z
600mA PWM Step-Down Converters in 2mm x 2mm WLP for WCDMA PA Power
4 _______________________________________________________________________________________
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, TA= -40°C to +85°C. Typical values are at TA =
+25°C, unless otherwise noted.) (Note 1)
Note 1: All devices are 100% production tested at TA= +25°C. Limits over the operating temperature range are guaranteed by design.
LDO2
Output Voltage V
Output Current 200 mA
Current Limit V
Dropout Voltage I
Line Regulation V
Load Regulation I
Power-Supply Rejection ΔV
LDO2
Output Noise 100Hz to 100kHz, C
Output Capacitor for Stable Operation
Shutdown Output Impedance V
REFBP
REFBP Output Voltage 0 ≤ I
REFBP Supply Rejection V
PARAMETER CONDITIONS MIN TYP MAX UNITS
/ ΔV
IN2
LDO2
V
= 5.5V, I
IN2
V
= 3.4V, I
IN2
= 0V 250 550 750 mA
LDO2
= 100mA, TA = +25°C 70 200 mV
LDO2
stepped from 3.5V to 5.5V, I
IN2
stepped from 50µA to 200mA 25 mV
LDO2
10Hz to 10kHz, C
0µA < I
0µA < I
= 0V 1 kΩ
EN2
REFBP
stepped from 2.55V to 5.5V 0.2 5 mV
IN2
LDO2
LDO2
< 10mA 100 nF
LDO2
< 200mA 1 µF
LDO2
≤ 1µA 1.237 1.250 1.263 V
= 1mA; = 100mA
= 1µF, I
LDO2
LDO2
= 1µF, I
MAX8805YEWEAA+T 1.746 1.8 1.854
MAX8805YEWEAC+T 2.619 2.7 2.781
MAX8805YEWEAD+T 2.716 2.8 2.884
MAX8805YEWEBE+T 2.765 2.85 2.936
MAX8805YEWEGG+T 2.910 3.0
= 100mA 2.4 mV
LDO2
= 30mA 70 dB
LDO2
= 30mA 35 µV
LDO2
V
3.090
RMS
MAX8805Y/MAX8805Z
600mA PWM Step-Down Converters in
2mm x 2mm WLP for WCDMA PA Power
_______________________________________________________________________________________
5
Typical Operating Characteristics
(V
IN1A
= V
IN1B
= V
IN2
= 3.6V, VPA= 1.2V, V
LDO1
= 2.85V, V
LDO2
= 2.85V, RPA= 7.5Ω, circuit of Figure 5, TA= +25°C, unless other-
wise noted.)
0
40
20
80
60
120
100
140
0 0.4 0.60.2 0.8 1.0 1.2 1.4 1.6 1.8
BYPASS MODE DROPOUT VOLTAGE
vs. PA LOAD CURRENT
MAX8805Y/Z toc01
PA LOAD CURRENT (A)
BYPASS MODE DROPOUT VOLTAGE (mV)
V
IN1
= 3.2V
V
IN1
= 3.6V
60
70
80
90
100
0.5 1.5 2.5 3.51.0 2.0 3.0 4.0 4.5
PA STEP-DOWN CONVERTER EFFICIENCY
vs. OUTPUT VOLTAGE (MAX8805Z)
MAX8805Y/Z toc02
OUTPUT VOLTAGE (V)
EFFICIENCY (%)
BYPASS MODE
V
IN1
= 4.2V
V
IN1
= 3.6V
V
IN1
= 3.2V
RPA = 7.5Ω
60
70
80
90
100
0.5 1.5 2.5 3.51.0 2.0 3.0 4.0 4.5
PA STEP-DOWN CONVERTER EFFICIENCY
vs. OUTPUT VOLTAGE (MAX8805Y)
MAX8805Y/Z toc03
OUTPUT VOLTAGE (V)
EFFICIENCY (%)
BYPASS MODE
V
IN1
= 4.2V
V
IN1
= 3.6V
V
IN1
= 3.2V
RPA = 7.5Ω
60
70
80
90
100
0.5 1.5 2.5 3.51.0 2.0 3.0 4.0 4.5
PA STEP-DOWN CONVERTER EFFICIENCY
vs. OUTPUT VOLTAGE (MAX8805Z)
MAX8805Y/Z toc04
OUTPUT VOLTAGE (V)
EFFICIENCY (%)
BYPASS MODE
V
IN1
= 4.2V
V
IN1
= 3.6V
V
IN1
= 3.2V
RPA = 10Ω
60
70
80
90
100
0.5 1.5 2.5 3.51.0 2.0 3.0 4.0 4.5
PA STEP-DOWN CONVERTER EFFICIENCY
vs. OUTPUT VOLTAGE (MAX8805Y)
MAX8805Y/Z toc05
OUTPUT VOLTAGE (V)
EFFICIENCY (%)
BYPASS MODE
V
IN1
= 4.2V
V
IN1
= 3.6V
V
IN1
= 3.2V
RPA = 10Ω
50
60
80
70
90
100
0200100 300 400 500 600
PA STEP-DOWN CONVERTER EFFICIENCY
vs. LOAD CURRENT (MAX8805Z)
MAX8805Y/Z toc06
LOAD CURRENT (mA)
EFFICIENCY (%)
V
IN1
= 4.2V
V
IN1
= 3.6V
V
IN1
= 3.2V
VPA = 1.8V
50
60
80
70
90
100
0 200100 300 500400 600
PA STEP-DOWN CONVERTER EFFICIENCY
vs. LOAD CURRENT (MAX8805Y)
MAX8805Y/Z toc07
LOAD CURRENT (mA)
EFFICIENCY (%)
V
IN1
= 4.2V
V
IN1
= 3.6V
V
IN1
= 3.2V
VPA = 1.8V
50
60
80
70
90
100
0200100 300 500400 600
PA STEP-DOWN CONVERTER EFFICIENCY
vs. LOAD CURRENT (MAX8805Z)
MAX8805Y/Z toc08
LOAD CURRENT (mA)
EFFICIENCY (%)
V
IN1
= 4.2V
V
IN1
= 3.6V
V
IN1
= 3.2V
VPA = 1.2V
50
60
80
70
90
100
0200100 300 500400 600
PA STEP-DOWN CONVERTER EFFICIENCY
vs. LOAD CURRENT (MAX8805Y)
MAX8805Y/Z toc09
LOAD CURRENT (mA)
EFFICIENCY (%)
V
IN1
= 4.2V
V
IN1
= 3.6V
V
IN1
= 3.2V
VPA = 1.2V
MAX8805Y/MAX8805Z
600mA PWM Step-Down Converters in 2mm x 2mm WLP for WCDMA PA Power
6 _______________________________________________________________________________________
Typical Operating Characteristics (continued)
(V
IN1A
= V
IN1B
= V
IN2
= 3.6V, VPA= 1.2V, V
LDO1
= 2.85V, V
LDO2
= 2.85V, RPA= 7.5Ω, circuit of Figure 5, TA= +25°C, unless other-
wise noted.)
50
60
80
70
90
100
0 200100 300 500400 600
PA STEP-DOWN CONVERTER EFFICIENCY
vs. LOAD CURRENT (MAX8805Z)
MAX8805Y/Z toc10
LOAD CURRENT (mA)
EFFICIENCY (%)
V
IN1
= 4.2V
V
IN1
= 3.6V
V
IN1
= 3.2V
VPA = 0.6V
50
60
80
70
90
100
0 200100 300 500400 600
PA STEP-DOWN CONVERTER EFFICIENCY
vs. LOAD CURRENT (MAX8805Y)
MAX8805Y/Z toc11
LOAD CURRENT (mA)
EFFICIENCY (%)
V
IN1
= 4.2V
V
IN1
= 3.6V
V
IN1
= 3.2V
VPA = 0.6V
1.25
1.20
1.15
1.10
1.05 0 300100 200 400 500 600
PA STEP-DOWN CONVERTER OUTPUT
VOLTAGE vs. LOAD CURRENT
MAX8805Y/Z toc12
LOAD CURRENT (mA)
OUTPUT VOLTAGE (V)
MAX8805Y
MAX8805Z
0.5
1.5
1.0
2.5
2.0
3.5
3.0
4.0
00.80.4 1.2 1.6 2.0
PA STEP-DOWN CONVERTER OUTPUT
VOLTAGE vs. REFIN VOLTAGE
MAX8805Y/Z toc13
REFIN VOLTAGE (V)
OUTPUT VOLTAGE (V)
-100
-60
-80
0
-20
-40
20
40
80
60
100
0.4 0.6 0.70.5 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5
REFIN vs. REFIN TO OUT GAIN (MAX8805Z)
MAX8805Y/Z toc14
REFIN VOLTAGE (V)
OUTPUT VOLTAGE ERROR (mV)
V
IN1
= 3.2V, NO LOAD
V
IN1
= 4.2V, NO LOAD
-50
-30
-10
10
30
50
0.4 0.6 0.70.5 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5
REFIN vs. REFIN TO OUT GAIN (MAX8805Y)
MAX8805Y/Z toc15
REFIN VOLTAGE (V)
OUTPUT VOLTAGE ERROR (mV)
V
IN1
= 3.2V, NO LOAD
V
IN1
= 4.2V, NO LOAD
400ns/div
PA STEP-DOWN CONVERTER LIGHT-LOAD
SWITCHING WAVEFORMS (MAX8805Z)
V
PA
AC-COUPLED
I
LX
200mA/div
20mV/div
2V/div
MAX8805Y/Z toc16
V
LX
VPA = 1.2V, IPA = 50mA
400ns/div
PA STEP-DOWN CONVERTER LIGHT-LOAD
SWITCHING WAVEFORMS (MAX8805Y)
V
PA
AC-COUPLED
I
LX
200mA/div
20mV/div
2V/div
MAX8805Y/Z toc17
V
LX
VPA = 1.2V, IPA = 50mA
400ns/div
PA STEP-DOWN HEAVY-LOAD
SWITCHING WAVEFORMS (MAX8805Z)
V
PA
AC-COUPLED
I
LX
500mA/div
20mV/div
2V/div
MAX8805Y/Z toc18
V
LX
VPA = 1.2V, IPA = 500mA
MAX8805Y/MAX8805Z
600mA PWM Step-Down Converters in
2mm x 2mm WLP for WCDMA PA Power
_______________________________________________________________________________________
7
Typical Operating Characteristics (continued)
(V
IN1A
= V
IN1B
= V
IN2
= 3.6V, VPA= 1.2V, V
LDO1
= 2.85V, V
LDO2
= 2.85V, RPA= 7.5Ω, circuit of Figure 5, TA= +25°C, unless other-
wise noted.)
_______________________________________________________________________________________
7
PA STEP-DOWN HEAVY-LOAD
V
AC-COUPLED
SWITCHING WAVEFORMS (MAX8805Y)
PA
MAX8805Y/Z toc19
20mV/div
V
PA_EN
V
PA
I
LX
PA STEP-DOWN SOFT-START
WAVEFORMS (MAX8805Z)
20μs/div
MAX8805Y/Z toc20
2V/div
1V/div
500mA/div
V
PA_EN
V
I
LX
V
LX
PA STEP-DOWN SOFT-START
WAVEFORMS (MAX8805Y)
PA
I
LX
500mA/div
2V/div
VPA = 1.2V, IPA = 500mA
400ns/div
MAX8805Y/Z toc21
2V/div
1V/div
200mA/div
20μs/div
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