_______________________________________________________________ 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.

76V, 300mW Boost Converter and Current

Monitor for APD Bias Applications

19-5132; Rev 1; 3/10

General Description

The MAX15059 constant-frequency pulse-width modu-

lating (PWM) step-up DC-DC converter features an

internal switch and a high-side current monitor with high-

speed adjustable current limiting. This device is capable

of generating output voltages up to 76V (300mW for

the MAX15059A and 200mW for the MAX15059B) and

provides current monitoring up to 4mA. The MAX15059

operates from 2.8V to 5.5V.

The constant-frequency (400kHz) current-mode PWM

architecture provides low-noise-output voltage that is

easy to filter. A high-voltage internal power MOSFET

allows this device to boost output voltages up to 76V.

Internal soft-start circuitry limits the input current when

the boost converter starts. The MAX15059 features a

shutdown mode to save power.

The MAX15059 includes a current monitor with more

than three decades of dynamic range and monitors

current ranging from 500nA to 4mA with high accuracy.

Resistor-adjustable current limiting protects the APD

from optical power transients. A clamp diode protects

the monitor’s output from overvoltage conditions. Other

protection features include cycle-by-cycle current limit-

ing of the boost converter switch, undervoltage lockout

(UVLO), and thermal shutdown if the die temperature

reaches +150NC.

The MAX15059 is available in a thermally enhanced,

lead-free, 16-pin TQFN-EP package and operates over

the -40NC to +85NC temperature range.

Applications

Avalanche Photodiode Biasing and Monitoring

PIN Diode Bias Supply

Low-Noise Varactor Diode Bias Supply

FBON Modules

GPON Modules

Features

S

Input Voltage Range: +2.8V to +5.5V

S

S

Internal 1I (typ) 80V MOSFET

S

Boost Converter Output Power: 300mW

S

200mW Version Available for Smaller Inductor

S

Accurate Q5% (1:1 and 5:1) High-Side Current

Monitor

S

Resistor-Adjustable Ultra-Fast APD Current Limit

(1µs Response Time)

S

Open-Drain Current-Limit Indicator Flag

S

400kHz Fixed-Switching Frequency

S

Constant PWM Frequency Provides Easy Filtering

in Low-Noise Applications

S

Internal Soft-Start

S

2µA (max) Shutdown Current

S

-40NC to +85NC Temperature Range

S

Small, Thermally Enhanced, 3mm x 3mm, Lead-

Free, 16-Pin TQFN-EP Package

Note: All devices operate over the -40°C to +85°C temperature

range.

+Denotes a lead(Pb)-free/RoHS-compliant package.

*EP = Exposed pad.

Ordering Information

Typical Operating Circuit

EVALUATION

KIT

AVAILABLE

CNTRL

IN

SGND

LX

RLIM

2.87kI

1kI

TO 5.5V

1µF

0.1µF

L1

4.7µH

DAC

CLAMP

OPTIONAL

(10nF)

MOUT

ILIM

SHDN

GPIO

GPIO

FB

BIAS

PGND

R2

348kI

R1

6.34kI

(76V MAX)

APD

ADC

D1

APD

µC

MAX15059

TIA

PART

MAXIMUM

POWER

(mW)

PIN-

PACKAGE

MAX15059AETE+

300

1:1

16 TQFN-EP*

MAX15059BETE+

200

5:1

16 TQFN-EP*