Datasheet MAX8805, MAX8805ZEWEEE+T Datasheet (Maxim)

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-

PACKAGE

PKG

CODE

SWI T C H I N G

F R EQ U EN C Y

( M H z)

MAX8805YEWExy+T*

16 WLP-16 W162B2+ 1

2

MAX8805ZEWExy+T*

16 WLP-16 W162B2+ 1

4

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

PARAMETER CONDITIONS MIN TYP MAX UNITS

INPUT SUPPLY

Input Voltage V

IN1A

, V

IN1B

, V

IN2

2.7 5.5 V

Input Undervoltage Threshold V

IN1A

, V

IN1B

, V

IN2

rising, 180mV typical hysteresis 2.52 2.63 2.70 V

TA = +25°C 0.1 4

Shutdown Supply Current V

PA_EN

= V

EN1

= V

EN2

= 0V

T

A

= +85°C 0.1

µA

V

PA_EN

= 0V, I

LDO1

= I

LDO2

= 0A 150 250

MAX8805Y 3500

V

EN1

= V

EN2

= 0V, IPA = 0A,

switching

MAX8805Z 5000

No-Load Supply Current

V

EN1

= V

EN2

= 0V, VHP = 3.6V 150

µA

THERMAL PROTECTION

Thermal Shutdown TA rising, 20°C typical hysteresis +160 °C

LOGIC CONTROL

PA_EN, EN1, EN2, HP Logic­Input High Voltage

2.7V ≤ V

IN1A

= V

IN1B

= V

IN2

≤ 5.5V 1.4 V

PA_EN, EN1, EN2, HP Logic­Input Low Voltage

2.7V ≤ V

IN1A

= V

IN1B

= V

IN2

≤ 5.5V 0.4 V

TA = +25°C 0.01 1

Logic-Input Current
(PA_EN, EN1, EN2, HP)

V

IL

= 0V or V

IH

= V

IN1A

= 5.5V

T

A

= +85°C 0.1

µA

REFIN

REFIN Common-Mode Range 0.1 2.2 V

REFIN to PA_ Gain (Falling Edge) V

REFIN

= 0.4V, 0.9V, 1.7V, 2.2V 1.96 2.00 2.04 V/V

REFIN Input Resistance 540 kΩ

REFIN
Dual Mode™ Threshold

V

REFIN

rising, 50mV hysteresis

0.45 x
V

IN2

0.465 x
V

IN2

0.48 x
V

IN2

V

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.

MAX8805Y/MAX8805Z

600mA PWM Step-Down Converters in

2mm x 2mm WLP for WCDMA PA Power

_______________________________________________________________________________________ 3

PARAMETER CONDITIONS MIN TYP MAX UNITS

LX

p-channel MOSFET switch, ILX = -40mA 0.18 0.6

On-Resistance

n-channel MOSFET rectifier, I

LX

= 40mA 0.15 0.6

Ω

TA = +25°C 0.1 5

LX Leakage Current

V

IN1A

= V

IN1B

= V

IN2

= 5.5V,

V

LX

= 0V

T

A

= +85°C 1

µA

p-Channel MOSFET Peak
Current Limit

V

LX

= 0V 0.7 0.9 1.1 A

n-Channel MOSFET Valley
Current Limit

0.5 0.7 0.9 A

Minimum On- and Off-Times 0.1 µs

Power-Up Delay From PA_EN rising to LX rising 150 250 µs

BYPASS

TA = +25°C 0.060 0.1

On-Resistance

p-channel MOSFET bypass,
I

OUT

= -90mA

T

A

= +85°C 0.1

Ω

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

TA = +25°C 0.01 10

Bypass Off-Leakage Current

V

IN1A

= V

IN1B

= V

IN2

= 5.5V,

V

PAA

= V

PAB

= 0V

T

A

= +85°C 1

µA

LDO1

MAX8805YEWEAA+T 1.746 1.8 1.854

MAX8805YEWEBC+T 2.425 2.5 2.575

MAX8805YEWECC+T 2.619 2.7 2.781

MAX8805YEWEDD+T 2.716 2.8 2.884

MAX8805YEWEEE+T 2.765 2.85 2.936

Output Voltage V

LDO1

V

IN2

= 5.5V, I

LDO1

= 1mA;

V

IN2

= 3.4V, I

LDO1

= 100mA

MAX8805YEWEGG+T 2.910 3.0

3.090

V

Output Current 200 mA

Current Limit V

LDO1

= 0V 250 550 750 mA

Dropout Voltage I

LDO1

= 100mA, TA = +25°C (V

LDO1

≥ 2.5V) 70 200 mV

Line Regulation V

IN2

stepped from 3.5V to 5.5V, I

LDO1

= 100mA 2.4 mV

Load Regulation I

LDO1

stepped from 50µA to 200mA 25 mV

Power-Supply Rejection
ΔV

LDO1

/ ΔV

IN2

10Hz to 10kHz, C

LDO1

= 1µF, I

LDO1

= 30mA 70 dB

Output Noise 100Hz to 100kHz, C

LDO1

= 1µF, I

LDO1

= 30mA 35 µV

RMS

0 < I

LDO1

< 10mA 100 nF

Output Capacitor for Stable
Operation

0 < I

LDO1

< 200mA 1 µF

Shutdown Output Impedance V

EN1

= 0V 1 kΩ

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)

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)

PARAMETER CONDITIONS MIN TYP MAX UNITS

LDO2

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

Output Voltage V

LDO2

V

IN2

= 5.5V, I

LDO2

= 1mA;

V

IN2

= 3.4V, I

LDO2

= 100mA

MAX8805YEWEGG+T 2.910 3.0

3.090

V

Output Current 200 mA

Current Limit V

LDO2

= 0V 250 550 750 mA

Dropout Voltage I

LDO2

= 100mA, TA = +25°C 70 200 mV

Line Regulation V

IN2

stepped from 3.5V to 5.5V, I

LDO2

= 100mA 2.4 mV

Load Regulation I

LDO2

stepped from 50µA to 200mA 25 mV

Power-Supply Rejection
ΔV

LDO2

/ ΔV

IN2

10Hz to 10kHz, C

LDO2

= 1µF, I

LDO2

= 30mA 70 dB

Output Noise 100Hz to 100kHz, C

LDO2

= 1µF, I

LDO2

= 30mA 35 µV

RMS

0µA < I

LDO2

< 10mA 100 nF

Output Capacitor for Stable
Operation

0µA < I

LDO2

< 200mA 1 µF

Shutdown Output Impedance V

EN2

= 0V 1 kΩ

REFBP

REFBP Output Voltage 0 ≤ I

REFBP

≤ 1µA 1.237 1.250 1.263 V

REFBP Supply Rejection V

IN2

stepped from 2.55V to 5.5V 0.2 5 mV

Note 1: All devices are 100% production tested at TA= +25°C. Limits over the operating temperature range are guaranteed by design.

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

400ns/div

PA STEP-DOWN HEAVY-LOAD

SWITCHING WAVEFORMS (MAX8805Y)

V

PA

AC-COUPLED

I

LX

500mA/div

20mV/div

2V/div

MAX8805Y/Z toc19

V

LX

VPA = 1.2V, IPA = 500mA

20μs/div

PA STEP-DOWN SOFT-START

WAVEFORMS (MAX8805Z)

V

PA_EN

V

PA

1V/div

2V/div

500mA/div

MAX8805Y/Z toc20

I

LX

20μs/div

PA STEP-DOWN SOFT-START

WAVEFORMS (MAX8805Y)

V

PA_EN

V

PA

1V/div

2V/div

200mA/div

MAX8805Y/Z toc21

I

LX

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

MAX8805Y/MAX8805Z

600mA PWM Step-Down Converters in
2mm x 2mm WLP for WCDMA PA Power

8 _______________________________________________________________________________________

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.)

10μs/div

PA STEP-DOWN CONVERTER OUTPUT

VOLTAGE TRANSIENT RESPONSE

V

REFIN

V

PA

500mV/div

500mV/div

500mA/div

MAX8805Y/Z toc26

I

LX

0.5V

1V

0.5V

20μs/div

PA STEP-DOWN CONVERTER FORCED

BYPASS-FET TRANSIENT RESPONSE

V

HP

V

PA

2V/div

2V/div

500mA/div

MAX8805Y/Z toc27

I

LX

0.5V

0V

0V

1.2V

1.2V

3.6V

10μs/div

PA STEP-DOWN CONVERTER LOAD

TRANSIENT RESPONSE (MAX8805Y)

I

PA

I

LX

500mA/div

500mA/div

100mV/div

MAX8805Y/Z toc25

V

PA

AC-COUPLED

0mA

500mA

0mA

10μs/div

PA STEP-DOWN CONVERTER LOAD

TRANSIENT RESPONSE (MAX8805Z)

I

PA

I

LX

500mA/div

500mA/div

100mV/div

MAX8805Y/Z toc24

V

PA

AC-COUPLED

0mA

500mA

0mA

10μs/div

PA STEP-DOWN CONVERTER LINE

TRANSIENT RESPONSE (MAX8805Z)

V

IN1

V

PA

AC-COUPLED

50mV/div

500mV/div

200mA/div

MAX8805Y/Z toc22

I

LX

4.0V

3.5V

4.0V

10μs/div

PA STEP-DOWN CONVERTER LINE

TRANSIENT RESPONSE (MAX8805Y)

V

IN1

V

PA

AC-COUPLED

50mV/div

500mV/div

200mA/div

MAX8805Y/Z toc23

I

LX

4.0V

3.5V

4.0V

MAX8805Y/MAX8805Z

600mA PWM Step-Down Converters in

2mm x 2mm WLP for WCDMA PA Power

_______________________________________________________________________________________

9

10μs/div

PA STEP-DOWN CONVERTER AUTOMATIC

BYPASS-FET TRANSIENT RESPONSE

V

REFIN

V

PA

2V/div

1V/div

500mA/div

MAX8805Y/Z toc28

I

LX

1.8V

0.6V

0.6V

1.2V

1.2V

3.6V

200μs/div

PA STEP-DOWN CONVERTER AUTOMATIC

BYPASS-FET TRANSIENT RESPONSE

V

REFIN

V

PA

1V/div

1V/div

500mA/div

MAX8805Y/Z toc29

I

LX

V

REFIN

IS A 0.4V TO
2V SINUSOIDAL
SIGNAL

3.6V

10μs/div

PA STEP-DOWN CONVERTER

SHUTDOWN RESPONSE (MAX8805Y)

V

PA_EN

V

PA

1V/div

2V/div

100mA/div

MAX8805Y/Z toc30

I

LX

0V

2V

1.2V

10μs/div

PA STEP-DOWN CONVERTER

SHUTDOWN RESPONSE (MAX8805Z)

V

PA_EN

V

PA

2V/div

2V/div

100mA/div

MAX8805Y/Z toc31

I

LX

0V

2V

1.2V

0

50

100

150

200

LDO1, LDO2 SUPPLY CURRENT

vs. SUPPLY VOLTAGE

MAX8805Y/Z toc32

SUPPLY VOLTAGE (V)

NO-LOAD SUPPLY CURRENT (μA)

2.0 3.5 4.02.5 3.0 4.5 5.0 5.5

0

30

90

60

120

150

LDO1, LDO2 DROPOUT VOLTAGE

vs. LOAD CURRENT

MAX8805Y/Z toc33

LOAD CURRENT (mA)

LDO1, LDO2 DROPOUT VOLTAGE (mV)

0 10050 150 200

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.)

MAX8805Y/MAX8805Z

600mA PWM Step-Down Converters in
2mm x 2mm WLP for WCDMA PA Power

10 ______________________________________________________________________________________

20μs/div

LDO1, LDO2 LOAD TRANSIENT

RESPONSE NEAR DROPOUT

100mA/div

50mV/div

100mA/div

MAX8805Y/Z toc38

0mA

80mA

V

IN2

= V

LDO1,2

+ 200mV

50mV/div

I

LDO1

V

LDO1

I

LDO2

V

LDO2

0mA

0mA

0mA

80mA

1ms/div

LDO1, LDO2 TURN ON AND

SHUTDOWN RESPONSE

2V/div

2V/div

2V/div

MAX8805Y/Z toc39

V

EN1,2

V

LDO1

V

LDO2

20μs/div

LDO LINE TRANSIENT RESPONSE

500mV/div

MAX8805Y/Z toc37

4.0V

4.0V

3.5V

I

LDO_

= 80mA

5mV/div

V

IN2

V

LDO_

LDO PSRR vs. FREQUENCY

MAX8805Y/Z toc34

FREQUENCY (kHz)

PSRR (dB)

1001010.1

20

30

40

50

60

70

80

10

0.01 1000

I

LDO

= 30mA

LDO OUTPUT NOISE SPECTRAL DENSITY

vs. FREQUENCY

MAX8805Y/Z toc35

FREQUENCY (kHz)

OUTPUT NOISE DENSITY NOISE (nV/√Hz)

1001010.1

1.0E+02

1.0E+03

1.0E+04

1.0E+01

0.01 1000

400μs/div

LDO1, LDO2 OUTPUT NOISE WAVEFORM

50mV/div

MAX8805Y/Z toc36

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.)

MAX8805Y/MAX8805Z

600mA PWM Step-Down Converters in

2mm x 2mm WLP for WCDMA PA Power

______________________________________________________________________________________ 11

Pin Description

PIN NAME FUNCTION

A1 REFBP

Reference Noise Bypass. Bypass REFBP to AGND with a 0.22µF ceramic capacitor to reduce noise on the
LDO outputs. REFBP is internally pulled down through a 1kΩ resistor during shutdown.

A2 AGND Low-Noise Analog Ground

A3 REFIN

DAC-Controlled Input. The output of the PA step-down converter is regulated to 2 x V

REFIN

. When V

REFIN

reaches 0.465 x V

IN2

, bypass mode is enabled.

A4 PGND Power Ground for PA Step-Down Converter

B1 LDO2

200mA LDO Regulator 2 Output. Bypass LDO2 with a 1µF ceramic capacitor as close as possible to LDO2
and AGND. LDO2 is internally pulled down through a 1kΩ resistor when this regulator is disabled.

B2 PA_EN

PA Step-Down Converter Enable Input. Connect to IN_ or logic-high for normal operation. Connect to GND
or logic-low for shutdown mode.

B3 EN2

LDO2 Enable Input. Connect to IN2 or logic-high for normal operation. Connect to AGND or logic-low for
shutdown mode.

B4 LX Inductor Connection. Connect an inductor from LX to the output of the PA step-down converter.

C1 IN2

Supply Voltage Input for LDO1, LDO2, and Internal Reference. Connect IN2 to a battery or supply voltage
from 2.7V to 5.5V. Bypass IN2 with a 2.2µF ceramic capacitor as close as possible to IN2 and AGND.
Connect IN2 to the same source as IN1A and IN1B.

C2 HP

High-Power Mode Set Input. Drive HP high to invoke forced bypass mode. Bypass mode connects the
input of the PA step-down converter directly to its output through the internal bypass MOSFET. Drive HP
low to disable the forced bypass mode.

C3, C4

IN1B,

IN1A

Supply Voltage Input for PA Step-Down Converter. Connect IN1_ to a battery or supply voltage from 2.7V to

5.5V. Bypass the connection of IN1_ with a 2.2µF ceramic capacitor as close as possible to IN1_, and
PGND. IN1A

and IN1B are internally connected together. Connect IN1_ to the same source as IN2.

D1 LDO1

200mA LDO Regulator 1 Output. Bypass LDO1 with a 1µF ceramic capacitor as close as possible to LDO1
and AGND. LDO1 is internally pulled down through a 1kΩ resistor when this regulator is disabled.

D2 EN1

LDO1 Enable Input. Connect to IN2 or logic-high for normal operation. Connect to AGND or logic-low for
shutdown mode.

D3, D4 PAB, PAA

PA Connection for Bypass Mode. Internally connected to IN1_ using the internal bypass MOSFET during
bypass mode. PA_ is connected to the internal feedback network. Bypass PA_ with a 2.2µF ceramic
capacitor as close as possible to PA_ and PGND.

MAX8805Y/MAX8805Z

600mA PWM Step-Down Converters in
2mm x 2mm WLP for WCDMA PA Power

12 ______________________________________________________________________________________

PWM LOGIC

STEP-DOWN CURRENT LIMIT

PWM ERROR

COMPARATOR

CURRENT-LIMIT CONTROL

LX

PGND

PAA

BYPASS FET

HP

REFIN

R2 R1

R3

R5R4

R6

R7

C2

C1

IN2

R8

R7

ERROR AMP

ERROR AMP

LDO1 CURRENT LIMIT

LDO2 CURRENT LIMIT

BANDGAP

BANDGAP

LDO1

R11

R10

LDO2

R9

R12

1.25V

REFERENCE

CONTROL

LOGIC

REFBP

AGND

BANDGAP

EN1

EN2

PA_EN

PAB

IN1B

IN1A

Figure 1. Block Diagram

MAX8805Y/MAX8805Z

600mA PWM Step-Down Converters in

2mm x 2mm WLP for WCDMA PA Power

______________________________________________________________________________________ 13

Detailed Description

The MAX8805Y/MAX8805Z are designed to dynamical­ly power the PA in WCDMA and NCDMA handsets. The
devices contain a high-frequency, high-efficiency step­down converter, and two LDOs. The step-down convert­er delivers over 600mA. The hysteretic PWM control
scheme provides extremely fast transient response,
while 2MHz and 4MHz switching-frequency options
allow the trade-off between efficiency and the smallest
external components. A 60mΩ bypass FET connects
the PA directly to the battery during high-power trans­mission.

Step-Down Converter Control Scheme

A hysteretic PWM control scheme ensures high effi­ciency, fast switching, fast transient response, low-out­put ripple, and physically tiny external components.
The control scheme is simple: when the output voltage
is below the regulation threshold, the error comparator
begins a switching cycle by turning on the high-side
switch. This high-side switch remains on until the mini­mum on-time expires and the output voltage is within
regulation, or the inductor current is above the current­limit threshold. Once off, the high-side switch remains
off until the minimum off-time expires and the output
voltage falls again below the regulation threshold.
During the off period, the low-side synchronous rectifier
turns on and remains on until the high-side switch turns
on again. The internal synchronous rectifier eliminates
the need for an external Schottky diode.

Voltage-Positioning Load Regulation

The MAX8805Y/MAX8805Z step-down converters utilize
a unique feedback network. By taking DC feedback
from the LX node through R1 in Figure 1, the usual
phase lag due to the output capacitor is removed, mak­ing the loop exceedingly stable and allowing the use of
very small ceramic output capacitors. To improve the
load regulation, resistor R3 is included in the feedback.
This configuration yields load regulation equal to half of
the inductor’s series resistance multiplied by the load
current. This voltage-positioning load regulation greatly
reduces overshoot during load transients or when
changing the output voltage from one level to another.
However, when calculating the required REFIN voltage,
the load regulation should be considered. Because
inductor resistance is typically well specified and the
typical PA is a resistive load, the MAX8805Y/MAX8805Z
V

REFIN

to V

OUT

gain is slightly less than 2V/V.

Step-Down Converter Bypass Mode

During high-power transmission, the bypass mode con­nects IN1A and IN1B directly to PAA and PAB with the

internal 60mΩ (typ) bypass FET, while the step-down
converter is forced into 100% duty-cycle operation. The
low on-resistance in this mode provides low dropout,
long battery life, and high output current capability.

Forced and Automatic Bypass Mode

Invoke forced bypass mode by driving HP high or
invoke automatic bypass mode by applying a high volt­age to REFIN. To prevent excessive output ripple as the
step-down converter approaches dropout, the
MAX8805Y/MAX8805Z enter bypass mode automatically
when V

REFIN

> 0.465 x V

IN2

(see Figure 2). Note that
IN2 is used instead of IN1 to prevent switching noise
from causing false enagement of automatic bypass
mode. For this reason, IN2 must be connected to the
same source as IN1.

Shutdown Mode

Connect PA_EN to GND or logic-low to place the
MAX8805Y/MAX8805Z PA step-down converter in shut­down mode. In shutdown, the control circuitry, internal
switching MOSFET, and synchronous rectifier turn off
and LX becomes high impedance. Connect PA_EN to
IN1_ or logic-high for normal operation.

Connect EN1 or EN2 to GND or logic-low to place
LDO1 or LDO2, respectively, in shutdown mode. In
shutdown, the outputs of the LDOs are pulled to ground
through an internal 1kΩ resistor.

When the PA step-down and LDOs are all in shutdown,
the MAX8805Y/MAX8805Z enter a very low power
state, where the input current drops to 0.1µA (typ).

0

1.0

0.5

2.0

1.5

3.0

2.5

3.5

4.5

4.0

5.0

010152052530354540 50

TIME (ms)

IN2 AND PA_

VOLTAGE (V)

REFIN VOLTAGE (V)

IN2
PA_
REFIN

0

0.5

1.0

1.5

2.0

2.5

Figure 2. V

IN2

and V

PA_

with Automatic Entry/Exit into Bypass

Mode

MAX8805Y/MAX8805Z

600mA PWM Step-Down Converters in
2mm x 2mm WLP for WCDMA PA Power

14 ______________________________________________________________________________________

Step-Down Converter Soft-Start

The MAX8805Y/MAX8805Z PA step-down converter has
internal soft-start circuitry that limits inrush current at
startup, reducing transients on the input source. Soft­start is particularly useful for supplies with high output
impedance such as Li+ and alkaline cells. See the Soft­Start Waveforms in the

Typical Operating Characteristics.

Analog REFIN Control

The MAX8805Y/MAX8805Z PA step-down converter uses
REFIN to set the output voltage. The output voltage is reg­ulated at twice the voltage applied at REFIN minus the
load regulation. This allows the converter to operate in
applications where dynamic voltage control is required.

Thermal Shutdown

Thermal shutdown limits total power dissipation in the
MAX8805Y/MAX8805Z. If the junction temperature
exceeds +160°C, thermal-shutdown circuitry turns off
the IC, allowing it to cool. The IC turns on and begins
soft-start after the junction temperature cools by 20°C.
This results in a pulsed output during continuous ther­mal-overload conditions.

Applications Information

Output Voltages

The MAX8805Y/MAX8805Z PA step-down converters
set the PA_ output voltage to twice the voltage applied
to REFIN.

LDO1 and LDO2 output voltages are determined by the
part number suffix, as shown in Table 1.

LDO Dropout Voltage

The regulator’s minimum input/output differential (or
dropout voltage) determines the lowest usable supply
voltage. In battery-powered systems, this determines
the useful end-of-life battery voltage. Because the
MAX8805Y/MAX8805Z LDOs use a p-channel MOSFET
pass transistor, their dropout voltages are a function of
drain-to-source on-resistance (R

DS

(ON)) multiplied by the

load current (see the

Typical Operating Characteristics

).

Inductor Selection

The MAX8805Y operates with a switching frequency of
2MHz and utilizes a 2.2µH inductor. The MAX8805Z
operates with a switching frequency of 4MHz and uti­lizes a 1µH inductor. The higher switching frequency of
the MAX8805Z allows the use of physically smaller
inductors at the cost of slightly lower efficiency. The
lower switching frequency of the MAX8805Y results in
greater efficiency at the cost of a physically larger
inductor. See the

Typical Operating Characteristics

for
efficiency graphs for both the MAX8805Y and
MAX8805Z.

The inductor’s DC current rating only needs to match the
maximum load of the application because the
MAX8805Y/MAX8805Z feature zero current overshoot
during startup and load transients. For optimum transient
response and high efficiency, choose an inductor with
DC series resistance in the 50mΩ to 150mΩ range. See
Table 2 for suggested inductors and manufacturers.

Output Capacitor Selection

For the PA step-down converter, the output capacitor
(CPA) is required to keep the output voltage ripple small
and ensure regulation loop stability. CPAmust have low
impedance at the switching frequency. Ceramic capaci­tors with X5R or X7R dielectric are highly recommended
due to their small size, low ESR, and small temperature
coefficients. Due to the unique feedback network, the
output capacitance can be very low. A 2.2µF capacitor
is recommended for most applications. For optimum
load-transient performance and very low output ripple,
the output capacitor value can be increased.

For LDO1 and LDO2, the minimum output capacitance
required is dependent on the load currents. For loads
less than 10mA, it is sufficient to use a 0.1µF capacitor
for stable operation over the full temperature range.
With rated maximum load currents, a minimum of 1µF is
recommended. Reduce output noise and improve load­transient response, stability, and power-supply rejec­tion by using larger output capacitors.

Note that some ceramic dielectrics exhibit large capaci­tance and ESR variation with temperature. With dielectrics
such as Z5U and Y5V, it is necessary to use 2.2µF or larg­er to ensure stability at temperatures below -10°C. With
X7R or X5R dielectrics, 1µF is sufficient at all operating
temperatures. These regulators are optimized for ceramic
capacitors. Tantalum capacitors are not recommended.

Table 1. LDO1 and LDO2 Output Voltage
Selection

Note: Contact the factory for other output-voltage options.

PART

FREQUENCY

(MHz)

LDO1

(V)

LDO2

(V)

MAX8805YEWEAA+T

2 1.80 1.80

MAX8805YEWEAE+T

2 1.80 2.85

MAX8805YEWEEE+T

2 2.85 2.85

MAX8805ZEWEAA+T

4 1.80 1.80

MAX8805ZEWEAE+T

4 1.80 2.85

MAX8805ZEWEEE+T

4 2.85 2.85

MAX8805Y/MAX8805Z

600mA PWM Step-Down Converters in

2mm x 2mm WLP for WCDMA PA Power

______________________________________________________________________________________ 15

Input Capacitor Selection

The input capacitor (C

IN1

) of the PA converter reduces
the current peaks drawn from the battery or input
power source and reduces switching noise in the
MAX8805Y/MAX8805Z. The impedance of C

IN1

at the
switching frequency should be kept very low. Ceramic
capacitors with X5R or X7R dielectric are highly recom­mended due to their small size, low ESR, and small
temperature coefficients. A 2.2µF capacitor is recom­mended for most applications. For optimum noise
immunity and low input ripple, the input capacitor value
can be increased.

For the LDOs, use an input capacitance equal to the
value of the sum of the output capacitance of LDO1 and

LDO2. Larger input capacitor values and lower ESR pro­vide better noise rejection and line transient response.

Note that some ceramic dielectrics exhibit large capaci­tance and ESR variation with temperature. With
dielectrics such as Z5U and Y5V, it may be necessary to
use two times the sum of the output capacitor values of
LDO1 and LDO2 (or larger) to ensure stability at temper­atures below -10°C. With X7R or X5R dielectrics, a
capacitance equal to the sum is sufficient at all operating
temperatures.

Table 2. Suggested Inductors

MANUFACTURER

SERIES

INDUCTANCE

(µH)

ESR

(Ω)

CURRENT RATING

(mA)

DIMENSIONS

(mm)

Coilcraft LPO3310

1.0

1.5

2.2

0.07

0.10

0.13

1600
1400
1100

3.3 x 3.3 x 1.0 = 11mm

3

MIPF2520

1.0

1.5

2.2

0.05

0.07

0.08

1500
1500
1300

2.5 x 2.0 x 1.0 = 5mm

3

MIPS2520

1.3

2.0

0.09

0.11

1500
1200

2.5 x 2.0 x 1.0 = 5mm

3

FDK

MIPF2016

1.0

2.2

0.11 1100

2.0 x 1.6 x 1.0 = 3.2mm

3

Hitachi

KSLI-252010

1.5

2.2

0.115

0.080

—

2.5 x 2.0 x 1.0 = 5mm

3

Murata LQH32C_53

1.0

2.2

0.06

0.10

1000

790

3.2 x 2.5 x 1.7 = 14mm

3

Sumida CDRH2D09

1.2

1.5

2.2

0.08

0.09

0.12

590
520
440

3.0 x 3.0 x 1.0 = 9mm

3

CDRH2D11

1.5

2.2

3.3

0.05

0.08

0.10

680
580
450

3.2 x 3.2 x 1.2 = 12mm

3

Taiyo Yuden

CB2518T

2.2

4.7

0.09

0.13

510
340

2.5 x 1.8 x 2.0 = 9mm

3

D3010FB 1.0 0.20 1170

3.0 x 3.0 x 1.0 = 9mm

3

D2812C

1.2

2.2

0.09

0.15

860
640

3.0 x 3.0 x 1.2 = 11mm

3

D310F

1.5

2.2

0.13

0.17

1230
1080

3.6 x 3.6 x 1.0 = 13mm

3

TOKO

D312C

1.5

2.2

0.10

0.12

1290
1140

3.6 x 3.6 x 1.2 = 16mm

3

MAX8805Y/MAX8805Z

600mA PWM Step-Down Converters in
2mm x 2mm WLP for WCDMA PA Power

16 ______________________________________________________________________________________

Thermal Considerations

In most applications, the MAX8805Y/MAX8805Z do not
dissipate much heat due to their high efficiency.
However, in applications where the MAX8805Y/
MAX8805Z run at high ambient temperature with heavy
loads, the heat dissipated may exceed the maximum
junction temperature of the IC. If the junction tempera­ture reaches approximately +160°C, all power switches
are turned off and LX and PA_ become high imped­ance, and LDO1 and LDO2 are pulled down to ground
through an internal 1kΩ pulldown resistor.

The MAX8805Y/MAX8805Z maximum power dissipation
depends on the thermal resistance of the IC package
and circuit board, the temperature difference between
the die junction and ambient air, and the rate of airflow.
The power dissipated in the device is:

P

DISS

= PPAx (1/ηPA- 1) + I

LDO1

x (V

IN2

- V

LDO1

) +

I

LDO2

x (V

IN2-VLDO2

)

where ηPAis the efficiency of the PA step-down con­verter and PPAis the output power of the PA step-down
converter.

The maximum allowed power dissipation is:

P

MAX

= (T

JMAX

- TA) / θ

JA

where (T

JMAX

- TA) is the temperature difference

between the MAX8805Y/MAX8805Z die junction and
the surrounding air; θJAis the thermal resistance of the
junction through the PCB, copper traces, and other
materials to the surrounding air.

PCB Layout

High switching frequencies and relatively large peak
currents make the PCB layout a very important part of
design. Good design minimizes excessive EMI on the
feedback paths and voltage gradients in the ground
plane, resulting in a stable and well-regulated output.
Connect C

IN1

close to IN1A/IN1B and PGND. Connect
the inductor and output capacitor as close as possible
to the IC and keep their traces short, direct, and wide.
Keep noisy traces, such as the LX node, as short as
possible. Figure 3 illustrates an example PCB layout
and routing scheme.

MAX8805Y/MAX8805Z

600mA PWM Step-Down Converters in

2mm x 2mm WLP for WCDMA PA Power

______________________________________________________________________________________ 17

REFIN

VIN

PA_EN

EN1

LDO1

LDO2

HP

5.5mm

EN2

AGND

PGND

3.8mm

C

IN2

C

PA

C

BYP

C

LDO2

C

LDO1

VPA

L

PA

C

IN1

Figure 3. Recommended PCB Layout

MAX8805Y/MAX8805Z

600mA PWM Step-Down Converters in
2mm x 2mm WLP for WCDMA PA Power

18 ______________________________________________________________________________________

2.2μF

2MHz OR 4MHz

BUCK

1μH OR

2.2μH*

LX

PBB

PGND

PBA

IN1A

IN1B

EN2

REFIN

2.2μF

REF

0.22μF

REFBP

AGND

LDO1

0.1μF

0.1μF

LDO2

IN2

1μF

PA_EN

HP

EN1

CONTROL

EN/BIAS

IN

PA2

EN/BIAS

IN

PA1

GPIO

GPIO

GPIO

GPIO

DAC

BASEBAND

PROCESSOR

Li+ BATTERY

LDO1

LDO2

MAX8805Y/MAX8805Z

*1μH FDK MIPS 2520D1R0

2.2μH FDK MIPF 2520D2R2

Figure 4. Typical Application Circuit Using LDOs for PA Enable/Bias

MAX8805Y/MAX8805Z

600mA PWM Step-Down Converters in

2mm x 2mm WLP for WCDMA PA Power

______________________________________________________________________________________ 19

2.2μF

2MHz OR 4MHz

BUCK

1μH OR

2.2μH*

LX

PBB

PGND

PBA

IN1A

IN1B

EN2

REFIN

2.2μF

REF

0.22μF

REFBP

AGND

LDO1

1μF

1μF

LDO2

IN2

2.2μF

PA_EN

HP

EN1

CONTROL

RF TRANSMITTER

IN

IN

PA

GPIO

GPIO

GPIO

GPIO

DAC

BASEBAND

PROCESSOR

Li+ BATTERY

LDO1

LDO2

MAX8805Y/MAX8805Z

RF RECEIVER

IN

*1μH FDK MIPS 2520D1R0

2.2μH FDK MIPF 2520D2R2

Figure 5. Typical Application Circuit Using LDOs for RF Power

MAX8805Y/MAX8805Z

600mA PWM Step-Down Converters in
2mm x 2mm WLP for WCDMA PA Power

20 ______________________________________________________________________________________

REFBP AGND

LDO2

IN2

REFIN

EN2

IN1B

PA_EN

(BUMP IN BOTTOM)

16-Bump, 2mm × 2mm WLP

HP

LDO1 PABEN1

PGND

LX

IN1A

PAA

A1

A2 A3

A4

B1

B4

B3

B2

C1

C2

C3

C4

D1

D4

D3

D2

TOP VIEW

Pin Configuration

Chip Information

PROCESS: BiCMOS

MAX8805Y/MAX8805Z

600mA PWM Step-Down Converters in

2mm x 2mm WLP for WCDMA PA Power

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________

21

© 2007 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.

Package Information

(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information
go to www.maxim-ic.com/packages

.)

16L WLP.EPS