DC2151A - LINEAR TECHNOLOGY

dc2151af

DEMO MANUAL DC2151A

Description

LTC3331EUH

Nanopower Buck-Boost DC/DC with

Energy Harvesting Battery Charger

L, L, LTC, LTM, LT, Burst Mode, OPTI-LOOP, Over-The-Top and PolyPhase are registered

trademarks of Linear Technology Corporation. Adaptive Power, C-Load, DirectSense, Easy Drive,

FilterCAD, Hot Swap, LinearView, µModule, Micropower SwitcherCAD, Multimode Dimming, No

Latency Δ∑, No Latency Delta-Sigma, No RSENSE, Operational Filter, PanelProtect, PowerPath,

PowerSOT, SmartStart, SoftSpan, Stage Shedding, SwitcherCAD, ThinSOT, UltraFast and VLDO

are trademarks of Linear Technology Corporation. Other product names may be trademarks of

the companies that manufacture the products.

BoarD photo

Figure1. DC2151A Demoboard

Demonstration Circuit DC2151A is a nanopower buck-

boost DC/DC with energy harvesting battery charger

featuring the LT C

3331. The LTC3331 integrates a high

voltage energy harvesting power supply plus a DC/DC

converter powered by a rechargeable cell battery to create

a single output supply for alternative energy applications.

The energy harvesting power supply, consisting of an

integrated low-loss full-wave bridge with a high voltage

buck converter, harvests energy from piezoelectric, solar

or magnetic sources. The rechargeable cell input powers a

buck-boost converter capable of operating down to 1.8V

at its input. Either DC/DC converter can deliver energy to

a single output. The buck operates when harvested energy

is available, reducing the quiescent current drawn on the

battery to essentially zero. The buck-boost takes over

when harvested energy goes away.

A 10mA shunt allows simple battery charging with harvest

energy while a low battery disconnect function protects the

battery from deep discharge. A supercapacitor balancer

is also integrated, allowing for increased output storage.

Voltage and current settings for input and output as well

as the battery float voltage are programmable via pin-

strapped logic inputs.

The LTC3331EUH is available in a 5mm × 5mm 32-lead

QFN surface mount package with exposed pad.

Buck Efficiency vs ILOAD

ILOAD (A)

EFFICIENCY (%)

3331 G34

100

01µ 10µ 10m 100m1m100µ

VOUT = 1.8V

VOUT = 2.5V

VOUT = 3.3V

VOUT = 5V

VIN = 6V, L = 22µH, DCR = 0.19Ω

Figure2. Typical Efficiency of DC2151A

dc2151af

DEMO MANUAL DC2151A

performance summary

Specifications are at TA = 25°C

SYMBOL PARAMETER CONDITIONS MIN MAX UNITS

VIN Input Voltage Range 3.0 to 18.0 V

VOUT 1.8V Output Voltage Range OUT0=0, OUT1=0, OUT2=0 1.728 to 1.872 V

VOUT 2.5V Output Voltage Range OUT0=1, OUT1=0, OUT2=0 2.425 to 2.575 V

VOUT 2.8V Output Voltage Range OUT0=0, OUT1=1, OUT2=0 2.716 to 2.884 V

VOUT 3.0V Output Voltage Range OUT0=1, OUT1=0, OUT2=0 2.910 to 3.090 V

VOUT 3.3V Output Voltage Range OUT0=0, OUT1=0, OUT2=1 3.200 to 3.400 V

VOUT 3.6V Output Voltage Range OUT0=1, OUT1=0, OUT2=1 3.492 to 3.708 V

VOUT 4.5V Output Voltage Range OUT0=0, OUT1=1, OUT2=1 4.365 to 4.635 V

VOUT 5.0V Output Voltage Range OUT0=1, OUT1=1, OUT2=1 4.850 to 5.150 V

VBAT 3.45V Float Voltage Range FLOAT1=0, FLOAT=0 3.381 to 3.519 V

VBAT 4.00V Float Voltage Range FLOAT1=0, FLOAT=1 3.920 to 4.080 V

VBAT 4.1V Float Voltage Range FLOAT1=1, FLOAT=0 4.018 to 4.182 V

VBAT 4.2V Float Voltage Range FLOAT1=1, FLOAT=1 4.116 to 4.284 V

operating principle

Refer to the block diagram within the LTC3331 data sheet

for its operating principle.

The LTC3331 combines a buck switching regulator and

a buck-boost switching regulator to produce an energy

harvesting solution with battery backup. The converters are

controlled by a prioritizer that selects which converter to

use based on the availability of a battery and/or harvestable

energy. If harvested energy is available, the buck regulator

is active and the buck-boost is off. With a battery charger

and a supercapacitor balancer and an array of different

configurations, the LTC3331 suits many applications.

The synchronous buck converter is an ultralow quiescent

current power supply tailored to energy harvesting applica-

tions. It is designed to interface directly to a piezoelectric

or alternative A/C energy source, rectify and store the har-

vested energy on an external capacitor while maintaining a

regulated output voltage. It can also bleed off any excess

input power via an internal protective shunt regulator.

An internal full-wave bridge rectifier, accessible via AC1

and AC2 inputs, rectifies AC sources such as those from

a piezoelectric element. The rectified output is stored on

a capacitor at the VIN pin and can be used as an energy

reservoir for the buck converter. The bridge rectifier has

a total drop of about 800mV at typical piezo-generated

currents, but is capable of carrying up to 50mA.

When the voltage on VIN rises above the UVLO rising

threshold the buck converter is enabled and charge is

transferred from the input capacitor to the output capaci-

tor. When the input capacitor voltage is depleted below

the UVLO falling threshold the buck converter is disabled.

These thresholds can be set according to Table 4 of the

data sheet which offers UVLO rising thresholds from 4V

to 18V with large or small hysteresis windows.

Tw o internal rails, CAP and VIN2, are generated from VIN and

are used to drive the high side PMOS and low side NMOS

of the buck converter, respectively. Additionally the VIN2

rail serves as logic high for output voltage select bits UV

[3:0]. The VIN2 rail is regulated at 4.8V above GND while

the CAP rail is regulated at 4.8V below VIN. These are not

intended to be used as external rails. Bypass capacitors

should be connected to the CAP and VIN2 pins to serve

as energy reservoirs for driving the buck switches. When

VIN is below 4.8V, VIN2 is equal to VIN and CAP is held

at GND. VIN3 is an internal rail used by the buck and the

buck-boost. When the LTC3331 runs the buck, VIN3 will

be a Schottky diode drop below VIN2. When it runs as a

buck-boost VIN3 is equal to BAT.

dc2151af

DEMO MANUAL DC2151A

The buck regulator uses a hysteretic voltage algorithm

to control the output through internal feedback from the

VOUT sense pin. The buck converter charges an output

capacitor through an inductor to a value slightly higher

than the regulation point. It does this by ramping the

inductor current up to 250mA through an internal PMOS

switch and then ramping it down to 0mA through an

internal NMOS switch. When the buck brings the output

voltage into regulation, the converter enters a low quies-

cent current sleep state that monitors the output voltage

with a sleep comparator. During this operating mode,

load current is provided by the buck output capacitor.

When the output voltage falls below the regulation point,

the buck regulator wakes up and the cycle repeats. This

hysteretic method of providing a regulated output reduces

losses associated with FET switching and maintains an

output at light loads. The buck delivers a minimum of

50mA average load current when it is switching. VOUT

can be set from 1.8V to 5.0V via the output voltage select

bits OUT [2:0] according to Table 1 of the data sheet.

The buck-boost uses the same hysteretic algorithm as

the buck to control the output, VOUT, with the same sleep

comparator. The buck-boost has three modes of operation:

buck, buck-boost and boost. An internal mode compara-

tor determines the mode of operation based on BAT and

VOUT. In each mode, the inductor current ramps up to

IPEAK which is programmable via IPK [2:0]. See Table 3

of the data sheet.

An integrated battery charger operating from the VIN2 rail

charges the battery through the BB_IN pin. Connecting

BB_IN to the BAT_OUT pin, an internal MOSFET Switch will

then connect the battery charger to BAT_IN. The battery

charger is a shunt regulator which can sink up to 10mA.

The battery float voltage is programmable with two bits

and a third bit is used to program the battery connect and

disconnect voltage levels. This disconnect feature protects

the battery from permanent damage by deep discharge.

Disconnecting the battery from the BAT_OUT=BB_IN node

prevents the load as well as the LTC3331 quiescent current

from further discharging the battery.

OUTPUT VOLTAGE

50mV/DIV

AC-COUPLED

EH_ON

4V/DIV

IBB_IN

200mA/DIV

ICHARGE

1mA/DIV

100µs/DIV

ACTIVE ENERGY HARVESTER ENABLES

CHARGING OF THE BATTERY IN SLEEP

3331 TA01b

BAT = 3.6V

VOUT = 1.8V

ILOAD = 50mA

Figure3. Charging Battery with Harvested Energy

A SHIP mode is provided which manually disconnects the

battery. This may be helpful to prevent the battery from

discharging when no harvestable energy is available for

long periods of time, such as during shipping. Bring the

SHIP pin high to engage the SHIP mode. To disengage

the SHIP mode, bring the SHIP pin low. The BB_IN pin

needs to be brought above the low battery connect (LBC)

threshold to reconnect the battery.

Power good comparator, PGVOUT, produces a logic high

referenced to the highest of VIN2, BAT and VOUT less a

Schottky diode drop. PGVOUT will transition high the first

time the respective converter reaches the programmed

SLEEP threshold, signaling that the output is in regulation.

The pin will remain high until the voltage falls to 92% of

the desired regulated voltage.

An integrated supercapacitor balancer with 150nA of

quiescent current is available to balance a stack of two

supercapacitors. Typically the input, SCAP, will be tied to

VOUT to allow for increased energy storage at VOUT with

supercapacitors. The BAL pin is tied to the middle of the

stack and can source or sink 10mA to regulate the BAL

pin’s voltage to half that of the SCAP voltage. To disable

the balancer and its associated quiescent current, the

SCAP and BAL pins can be tied to ground.

operating principle

dc2151af

DEMO MANUAL DC2151A

Quick start proceDure

Using short twisted pair leads for any power connections,

with all loads and power supplies off, refer to Figure4 for

the proper measurement and equipment setup.

Follow the procedure below:

1. Before connecting PS1 to the DC2151A, PS1 must have

its current limit set to 300mA and PS2 must have its

current limit set to 100mA. For most power supplies

with a current limit adjustment feature the procedure

to set the current limit is as follows. Turn the voltage

and current adjustment to minimum. Short the output

terminals and turn the voltage adjustment to maximum.

Adjust the current limit to 300mA for PS1 and 100mA

for PS2. Turn the voltage adjustment to minimum and

remove the short between the output terminals. The

power supply is now current-limited to 300mA and

100mA respectively.

2. Initial Jumper, PS and LOAD settings:

JP1 = 0 JP2 = 0 JP3 = 0 JP4 = 0

JP5 = 0 JP6 = 0 JP7 = 0 JP8 = 0

JP9 = 0 JP10 = 0

JP11 = RUN JP12 = OFF

PS1 = OFF PS2 = OFF LOAD1 = OFF

Remove battery from battery holder

3. Connect PS1 to the VIN Terminals, then turn on PS1

and slowly increase voltage to 2.0V while monitoring

the input current. If the current remains less than 5mA,

increase PS1 to 5.0V.

4. Set LOAD1 to 50mA. Verify voltage on VOUT is within the

VOUT 1.8V range listed in the Performance Summary.

Verify that the output ripple voltage is between 10mV

and 50mV. Verify that PGVOUT is high. Decrease

LOAD1 to 5mA. Verify that PGVOUT and EH_ON are

high. Decrease PS1 to 2.0V. Verify that VOUT is 0V.

5. Set JP1, JP2, JP3, JP4 to 1. Slowly increase PS1 to

16V and verify that VOUT is off. Increase PS1 to 19V

and verify that VOUT is within the VOUT 1.8V range listed

in the Performance Summary. Decrease PS1 to 4.0V.

Verify that VOUT is 0V.

6. Decrease PS1 to 0V and disconnect PS1 from VIN. Set

the current limit of PS1 to 25mA as described above.

7. Move the connection for PS1 from VIN to AC1. Slowly

increase PS1 voltage to 2.0V while monitoring the

input current. If the current remains less than 5mA,

increase PS1 to 19V. Verify voltage on VOUT is within

the VOUT 1.8V range listed in the Performance Sum-

mary. Decrease PS1 to 0V, swap the AC1 connection

to AC2 and repeat the test. Decrease PS1 to 0V and

move the connection for PS1 from AC2 to VIN.

8. Set JP5 to 1, JP6 to 1, and JP7 to 1. Increase PS1 to

19V and set LOAD1 to 50mA. Verify voltage on VOUT is

within the VOUT 5.0V range listed in the Performance

Summary. Verify that the output ripple voltage is be-

tween 40mV and 90mV. Set PS1 to 0V.

9. Set the current limit of PS2 to 60mA as described

above. Set JP1 to 0, JP2, JP3 and JP4 to 1, JP5–JP7

to 1 and JP8–JP10 to 0. Set JP12 to CHARGE. Increase

PS1 to 12V and set LOAD1 to 0mA. Connect PS2 to

the BAT_IN Terminals, then turn on PS2 and slowly

increase voltage to 1.0V while monitoring the input

current. If the current remains less than 15mA, increase

PS2 until VM4 reads 2.7V. Verify that the current in

AM2 is approximately 660µA. Increase PS2 to 3.5V

and verify that VM4 is approximately 3.45V.

10. Set JP8–JP10 to 1. Increase PS1 to 12V and set LOAD1

to 0mA. Set PS2 to 3.7V. Verify that the current in

AM2 is approximately 330µA. Increase PS2 to 4.3V

and verify that VM4 is approximately 4.2V.

11. Set JP12 to FAST_CHRG. Set PS2 to 3.7V. Verify that

the current in AM2 is approximately 10mA. Set JP12

to CHARGE

12. Set the current limit of PS2 to 100mA as described

above. Set PS1 to 14V. Set JP1 to 1, JP2, JP3 and

JP4 to 0, JP5 to 0, JP6 and JP7 to 1. Set JP8 to 0. Set

PS2 to 3.2V. Set LOAD1 to 5mA. Remove PS1 lead

from the VIN turret. Verify voltage on VOUT is within

the VOUT 3.0V range listed in Performance Summary.

Verify that PGVOUT is high and EH_ON is low. Decrease

PS2 to 2.6V and verify that VOUT is 0V. Increase PS2 to

3.8V. Press and release PB1. Verify the VOUT is 3.0V.

dc2151af

DEMO MANUAL DC2151A

Quick start proceDure

13. Reconnect PS1 to VIN turret. Set PS1 to 14V. Set JP8

to 1. Set PS2 to 3.8V. Set LOAD1 to 5mA. Remove

PS1 lead from the VIN turret. Verify voltage on VOUT

is within the VOUT 3.0V range listed in Performance

Summary. Verify that PGVOUT is high and EH_ON is

low. Decrease PS2 to 3.1V and verify that VOUT is 0V.

Increase PS2 to 4.3V. Press and release PB1. Verify

the VOUT is 3.0V.

14. Set JP11 to SHIP and verify that VOUT is approximately 0V.

15. Decrease PS2 to 0V and disconnect PS2.

16. Set the current limit of PS1 to 300mA as described

above. Connect PS1 to the VIN Terminals. Set JP5 to

1, JP6 to 1 and JP7 to 1. Set PS1 to 14V. Set LOAD1

to 50mA. Add a jumper lead from VOUT to SCAP. Verify

that BAL is approximately half of VOUT.

17. Quickly remove PS1+ lead from VIN and verify that

VOUT remains above 1.2V for approximately 5 seconds.

18. Turn off PS1, PS2 and LOAD1. Reinstall battery in

battery holder.

Figure4. Proper Measurement Equipment Setup

dc2151af

DEMO MANUAL DC2151A

connection to a Dust mote (Dc9003a-B)

Figure5. DC2151A with Dust Mote

Attach a Dust

Mote to J1 of the DC2151A, refer to Figure5

for the proper setup. J1 is a keyed connector and is

connected to the left side of the P1 connector on the DUST

Mote. Figure13 is a schematic of the Dust Mote and the

DC2151A interconnections plus three extra connections

which 1) connect the SCAP to VOUT, 2) connect BAL to

the middle of the supercapacitors and 3) connect EH_ON

to OUT2. The DC2151A contains NC7SZ58P6X Universal

Configurable 2-Input logic gates that are input voltage

tolerant and allow level shifting between the LTC3331

and the Dust Mote.

Remove the battery from the BH1 holder on the bottom

side of the DC2151A. On the DC2151A, set JP1 to 1, JP2

to 0, JP3 to 1, JP4 to 0, JP5 to1, JP6 to 0, JP7 to 0, JP8,

JP9 and JP10 to 0, JP11 to RUN.

Piezoelectric Transducer Evaluation

Mount a series connected MIDE V25W to a vibration

source and connect the electrical connections to the

AC1 and AC2 turrets. Activate the vibration source to

an acceleration of 1g and a frequency of 60Hz. Figure6

shows an open-circuit voltage of 10.6V for the

MIDE V25W

piezoelectric device that was tuned to 60Hz. In order to

set the VIN_UVLO_RISING and VIN_UVLO_FALLING

thresholds, the open-circuit voltage of the piezoelectric

device must be measured. The internal bridge network of

the LTC3331 will have approximately 800mV drop at an

input current of 300µA.

dc2151af

DEMO MANUAL DC2151A

connection to a Dust mote (Dc9003a-B)

VAC_OC 1G

5.00V/DIV

5ms/DIV

DC2051A FIG06

Figure6. MIDE V25W Open-Circuit AC Voltage with 1grms, 60Hz

Acceleration Applied

The peak-power-load voltage of a purely resistive source

is at one-half of the rectified no-load voltage. In this case,

the optimal average input-voltage regulation level would

be 4.9V. Using a VIN_UVLO_RISING threshold of 6V and

a VIN_UVLO_FALLING threshold of 5V (UV3=0, UV2=0,

UV1=1, UV0=0) yields an average input voltage close

to the theoretical optimal voltage.

Figure7 is a plot of the output power and load voltage

of the V25W piezoelectric transducer into a 42.2kΩ load

for various rms acceleration levels. The output power

compares well with the input power that is charging CIN

during the sleep cycle between VIN_UVLO_FALLING and

VIN_UVLO_RISING thresholds at an acceleration force of

1grms, shown in Figure8 below.

In Figure8, the input capacitor is being recharged from

the V25W piezoelectric transducer. The input capacitor is

charging from 4.48V to 5.92V in 208 milliseconds. The

power delivered from the V25W is 648µW.

CIN =CIN •(V

IN12−V

IN22)

2•∆t

CIN =18µF •(5.922−4.482)

2•208ms

CIN =648µW

Assuming that the circuit is configured as shown in

Figure9, it will take a significant amount of time for the

piezo transducer to charge the 0.09F supercapacitor on

the output of the LTC3331. As used above, the 22µF input

capacitor is only 18µF at an applied voltage of 5V, so

every VIN_UVLO_RISING and FALLING event produces

26 micro-coulombs [(5.92V – 4.48V) • 18µF)] that may be

transferred from the input capacitor to the output capacitor,

FORCE (g)

0.250

700

600

500

400

300

200

100

00.625 0.875

0.375 0.500 0.750 1.000

POWER (µW)

LOAD VOLTAGE (VRMS)

0.000

1.000

2.000

3.000

4.000

6.000

5.000

DC2051A G01

POWER (µW)

LOAD VOLTAGE (VRMS)

Figure7. MIDE V25W Output Power into a 42.2kΩ Load with

1grms, 60Hz Acceleration Applied the MIDE V25W Piezoelectric

Transducer, [√2 • sin(2� • 60Hz • t)]

VOUT

1.00V/DIV

EH_ON

5.00V/DIV

VIN

2.00V/DIV

50.0ms/DIV DC2051A F08

Figure8. MIDE V25W Charging the 18µF input capacitance from

4.48V to 5.92V in 208ms

dc2151af

DEMO MANUAL DC2151A

minus the losses of the buck regulator in the LTC3331.

The buck regulator efficiency is approximately 90% at VIN

equal to 5V and VOUT between 2.5V and 3.6V. Thus, for

every UVLO event, 23.3 micro-coulombs are added to the

output supercapacitor. Given a 0.09F output supercapacitor

charging to 3.6V, 324 milli-coulombs are required to fully

charge the supercapacitor. Assuming no additional load on

the output, it takes 13,906 (.324/23.3e–6) UVLO events to

charge the output supercapacitor to 3.6V. From Figure8, it

can be observed that each VIN_UVLO event takes 208ms,

so the total time to charge the output capacitor from 0V to

3.6V will be greater than 2900 seconds. Figure10 shows

the no-load charging of the output supercapacitor, which

takes approximately 3300 seconds. The above calculation

neglects the lower efficiency at low output voltages and

the time it takes to transfer the energy from the input

capacitor to the output supercapacitor, so predicting the

actual value within –12% is to be expected.

connection to a Dust mote (Dc9003a-B)

LTC3331

DC2051A F09

AC1

VIN

CAP

VIN2

AC2

SWA

VOUT

SWB

SCAP

BAL

PGVOUT

EH_ON

IPK2

IPK1

IPK0

OUT2

OUT1

OUT0

VIN3

22µF

25V

1µF

6.3V

4.7µF

6.3V UV3

UV2

UV1

UV0

BAT_IN

FLOAT1 FLOAT0 LBSEL SHIP GND

CHARGE

BB_IN

BAT_OUT

0.1µF

6.3V

180mF

2.7V

180mF

2.7V

HZ202F

100µH

22µH

2.5V

100µF

6.3V

22µF

6.3V

2µF

6.3V

PIEZO

MIDE V25W

Figure9. LTC3331 Circuit Charging Supercapacitor at No Load without a battery (Vout=3.6V)

VOUT

2.00V/DIV

EH_ON

5.00V/DIV

VIN

2.00V/DIV 500s/DIV DC2051A F10

Figure10. Scope Shots of LTC3331 Charging Supercapacitor at

No Load without a Battery (Vout = 3.6V)

dc2151af

DEMO MANUAL DC2151A

connection to a Dust mote (Dc9003a-B)

Figure11 shows the LTC3331 with a supercapacitor on

the output, a battery installed and the output voltage set

to 3.6V. The scope shots in Figure12 were taken after

applying a pulsed load of 15mA for 10ms. With the battery

attached and a pulsed load applied, the EH_ON signal

will switch back and forth from high to low every time

the VIN voltage transitions from the VIN_UVLO_RISING

to the VIN_UVLO_FALLING threshold. When the pulsed

load is applied, the output capacitor is depleted slightly

and the input capacitor must recharge the output cap.

Because the input capacitance is much less then the output

capacitance, the input capacitor will go through many

UVLO transitions to charge the output capacitor back up

to the sleep threshold. Once the output is charged to the

output sleep threshold, the EH_ON signal will again be

consistently high indicating that the energy harvesting

source is powering the output.

LTC3331

DC2051A F

AC1

VIN

CAP

VIN2

AC2

SWA

VOUT

SWB

SCAP

BAL

PGVOUT

EH_ON

IPK2

IPK1

IPK0

OUT2

OUT1

OUT0

VIN3

22µF

25V

1µF

6.3V

4.7µF

6.3V UV3

UV2

UV1

UV0

BAT_IN

FLOAT1 FLOAT0 LBSEL SHIP GND

CHARGE

BB_IN

BAT_OUT

0.1µF

6.3V

180mF

2.7V

180mF

2.7V

HZ202F

100µH

22µH

2.5V

100µF

6.3V

PULSE

15mA

10ms

22µF

6.3V

2µF

6.3V

Li-ION

BATTERY

PIEZO

MIDE V25W

Figure11. LTC3331 Circuit with a Supercapacitor, a Battery installed and a pulsed load applied (Vout=3.6V)

VOUT

50.0mV/DIV

LOAD CURRENT

20.0mA/DIV

EH_ON

5.00V/DIV

VIN

2.00V/DIV

1.00s/DIV DC2051A F12

Figure12. Charging a Supercapacitor with a battery installed

and a pulsed load (Vout=3.6V)

dc2151af

DEMO MANUAL DC2151A

connection to a Dust mote (Dc9003a-B)

Figure13 shows the LTC3331 with an output supercapacitor,

a Dust Mote attached, a battery installed and EH_ON

connected to OUT2. In this configuration, when EH_ON

is low, VOUT will be set to 2.5V and when EH_ON is high,

VOUT will be set to 3.6V.

The first marker in Figure14 is where the vibration source

was activated; VIN then rises above the VIN_UVLO_RISING

threshold. EH_ON will then go high causing VOUT to rise

towards 3.6V (VOUT started at 2.5V because the battery

had charged it up initially). At the same time EH_ON

goes high, PGVOUT will go low, since the new VOUT level

of 3.6V has not been reached. As the charge on VIN is

being transferred to VOUT, VIN is discharging and when

VIN reaches its UVLO_FALLING threshold, EH_ON will go

2.7V

LTC3331

DC2051A F13

AC1

VIN

CAP

VIN2

AC2

SWB

SWA

VOUT

SCAP

BAL

PGVOUT

EH_ON

IPK2

IPK1

IPK0

OUT2

OUT0

OUT1

VIN3

0.1µF

6.3V

UVLO RISING = 12V*

UVLO FALLING = 11V

IPEAK_BB = 100mA

22µF

25V

1µF

6.3V

4.7µF

6.3V UV3

UV2

UV1

UV0

BAT_IN

FLOAT1 FLOAT0 LBSEL SHIP GND

CHARGE

130k

BB_IN

BAT_OUT

VOUT = 3.6V FOR EH_ON = 1

VOUT = 2.5V FOR EH_ON = 0

22µF

6.3V

22µH

22µF

6.3V

3.45V

LiFePO4

+1µF

6.3V

MIDE V25W

NC7SZ58P6

×2

LINEAR TECHNOLOGY DC9003A-AB

DUST MOTE FOR WIRELESS MESH NETWORKS

PGOOD

EHORBAT

VSUPPLY

GND

*FOR PEAK POWER TRANSFER, CENTER THE UVLO WINDOW

AT HALF THE RECTIFIED OPEN CIRCUIT VOLTAGE OF THE PIEZO

Figure13. Dust Mote Setup with a Supercapacitor, a battery and EH_ON connected to OUT2

VOUT

1.00V/DIV

VIN

2.00V/DIV

PGVOUT

5.00V/DIV

EH_ON

5.00V/DIV

200s/DIV DC2051A F14

Figure14. MIDE 25W Charging Output Supercapacitor from 2.5V

to 3.6 V with DUST Mote Attached

dc2151af

DEMO MANUAL DC2151A

Figure 15 shows the discharging of VOUT when the

vibration source is removed and VIN drops below the

UVLO_FALLING threshold, causing EH_ON to go low.

The supercapacitor on VOUT will discharge down to the

new target voltage of 2.5V, at which point the buck-boost

regulator will turn on, supplying power to the Dust Mote.

The discharging of the supercapacitor on VOUT provides

an energy source for short term loss of the vibration

source and extends the life of the battery.

Figure16 is the same Dust mote configuration as

Figure 13 but without the output supercapacitor.

Figure17 shows the charging of the output without

the supercapacitor attached.

low, causing the targeted VOUT to again be 2.5V. Given

that the output capacitor is very large and the average

load is less than the input power supplied by the MIDE

piezoelectric transducer, the output voltage will increase

to the higher setpoint of 3.6V over many cycles. During

the transition from the BAT setpoint of 2.5V to the energy

harvester setpoint of 3.6V, VOUT is above the 2.5V PGVOUT

threshold, hence, PGVOUT will go high every time EH_ON

goes low. This cycle will be repeated until VOUT reaches

the PGVOUT threshold for the VOUT setting of 3.6V. When

a pulse load is applied that is greater than the energy

supplied by the input capacitor, VIN will drop below the

VIN_UVLO_FALLING threshold, EH_ON will go low and

the buck-boost regulator will be ready to support the load

requirement from the battery, but will not start to switch

until the supercapacitor is discharged to 2.5V. In this way,

the circuit can store a lot of harvested energy and use it

for an extended period of time before switching over to

the battery energy. The supercapacitor could be sized to

accommodate known repeated periods of time that the

energy harvester source will not be available, such as

overnight when a vibrating machine is turned off or, in

the case of a solar application, when the lights are turned

off or the sun goes down.

While the EH_ON signal is low, the buck-boost circuit will

consume 750nA from the battery in the sleeping state.

The effects of a pulsed load are shown in Figure14 at

approximately 1850 seconds, where VIN is discharged and

the EH_ON signal pulses low to high for a brief period of

time, which occurred as a result of the Dust Mote radio

making a data transmission.

connection to a Dust mote (Dc9003a-B)

VOUT

1.00V/DIV

VIN

2.00V/DIV

PGVOUT

5.00V/DIV

EH_ON

5.00V/DIV

200s/DIV DC2051A F15

Figure15. Output Supercapacitor Discharging when the vibration

source is switched off

dc2151af

DEMO MANUAL DC2151A

LTC3331

DC2051A F16

AC1

VIN

CAP

VIN2

AC2

SWB

SWA

VOUT

SCAP

BAL

PGVOUT

EH_ON

IPK2

IPK1

IPK0

OUT2

OUT0

OUT1

VIN3

0.1µF

6.3V

NC7SZ58P6

×2

UVLO RISING = 12V*

UVLO FALLING = 11V

IPEAK_BB = 100mA

22µF

25V

1µF

6.3V

4.7µF

6.3V UV3

UV2

UV1

UV0

BAT_IN

FLOAT1 FLOAT0 LBSEL SHIP GND

CHARGE

130k

BB_IN

BAT_OUT

LINEAR TECHNOLOGY DC9003A-AB

DUST MOTE FOR WIRELESS MESH NETWORKS

PGOOD

EHORBAT

VSUPPLY

GND

VOUT = 3.6V FOR EH_ON = 1

VOUT = 2.5V FOR EH_ON = 0

100µF

6.3V

22µH

*FOR PEAK POWER TRANSFER, CENTER THE UVLO WINDOW

AT HALF THE RECTIFIED OPEN CIRCUIT VOLTAGE OF THE PIEZO

22µF

6.3V

3.45V

LiFePO4

+1µF

6.3V

MIDE V25W

Figure16. Dust Mote Setup without a Supercapacitor and with

EH_ON Connected to OUT2

VOUT

1.00V/DIV

VIN

2.00V/DIV

PGVOUT

5.00V/DIV

EH_ON

5.00V/DIV

100ms/DIV DC2051A F17

Figure17. Output Voltage Charging with Dust Mote Attached

without Supercapacitor

connection to a Dust mote (Dc9003a-B)

dc2151af

DEMO MANUAL DC2151A

parts list

ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER

Required Circuit Components

1 1 BAT1 CR2032 COIN LI-ION BATTERY POWERSTREAM, Lir2032

2 1 BTH1 BATTERY HOLDER COIN CELL 2032 SMD MPD INC, BU2032SM-HD-G

3 1 C1 SUPERCAP, 90mF, 5.5V, 20mm x 15mm CAP-XX, HZ202F-1

4 1 C2 CAP, CHIP, X5R, 150µF, 20%, 6.3V, 1210 SAMSUNG, CL32A157MQVNNNE

5 1 C3 CAP, CHIP, X5R, 1µF, 10%, 6.3V, 0402 SAMSUNG, CL05A105KQ5NNNC

6 1 C4 CAP, CHIP, X5R, 22µF, 10%, 25V, 1210 SAMSUNG, CL32A226KAJNNNE

7 1 C5 CAP, CHIP, X5R, 4.7µF, 10%, 6.3V, 0603 SAMSUNG, CL10A475KQ8NNNC

8 1 C6 CAP, CHIP, X5R, 0.1µF, 10%, 10V, 0402 TDK, C1005X5R1A104K

9 1 C7 CAP, CHIP, X5R, 22µF, 20%, 6.3V, 1206 SAMSUNG, CL31A226MQHNNNE

10 1 L1 INDUCTOR, 22µH, 0.800A, 0.36Ω, 3.9mm x 3.9mm COILCRAFT, LPS4018-223MLB

11 1 L2 INDUCTOR, 22µH, 0.75A, 0.19Ω, 4.8mm x 4.8mm COILCRAFT, LPS5030-223MLB

12 3 R2, R4, R6 RES, CHIP, 0Ω, 0603 VISHAY, CRCW06030000Z0EA

13 1 R10 RES, CHIP, 3.01K, 1/16W, 1%, 0402 VISHAY, CRCW04023K01FKED

14 1 U1 NANOPOWER BUCK-BOOST DC/DC WITH EH BATTERY CHARGER LINEAR TECHNOLOGY, LTC3331EUH#TRPBF

Additional Demo Board Circuit Components

1 0 C8, C9 CAP, CHIP, X5R, 0.1µF, 10%, 10V, 0402 (OPT) TDK, C1005X5R1A104K

2 0 C10 SUPERCAP/ULTRACAPACITOR, 330mF, 5.5V, 60mΩ DOUBLE CELL MURATA, DMF3R5R5L334M3DTA0

3 1 D1 DIODE, SCHOTTKY, 30V, 0.1A, SOD-523 CENTRAL, CMOSH-3

4 0 BTH2 SMT, CR2477 BATTERY HOLDER RENATA, SMTU2477-1

5 1 R1 RES, CHIP, 100Ω, 1/16W, 1%, 0402 VISHAY, CRCW0402100RFKED

6 0 R3, R5, R7 RES, CHIP, 0Ω, 0603 (DNP) VISHAY, CRCW06030000Z0EA

7 0 R8, R9 RES, CHIP, 7.5K, 1/16W, 1%, 0402 VISHAY, CRCW04027K50FKED

8 1 R11 RES, CHIP, 56.2Ω, 1/16W, 1%, 0402 VISHAY, CRCW040256R2FKED

9 2 R12, R14 RES, CHIP, 1.00M, 1/16W, 1%, 0402 VISHAY, CRCW04021M00FKED

10 1 R13 RES, CHIP, 100K, 1/16W, 1%, 0402 VISHAY, CRCW0402100KFKED

11 1 Q1 SMT, DUAL MOSFET, NCHANNET/PCHANNET, 60V, SuperSOT-6 FAIRCHILD, NDC7001C

12 1 Q2 SMT, BIPOLAR, PNP, 60V, SOT-23 CENTRAL, CMPT3906E

13 2 U2, U3 IC, UHS UNIV. CONFIG. TWO-INPUT GATES, SC70-6 FAIRCHILD, NC7SZ58P6X

1 13 E1-E6, E10-E17 TURRET, 0.09 DIA MILL-MAX, 2501-2-00-80-00-00-07-0

2 3 E7-E9 TURRET, 0.061 DIA MILL MAX, 2308-2-00-80-00-00-07-0

3 1 J1 HEADER, 12 PIN, DUST HEADER 2X6 SAMTEC, SMH-106-02-L-D-05

4 10 JP1-JP10 HEADER, 3 PIN 0.079 SINGLE ROW WURTH, 62000311121

5 2 JP11, JP12 HEADER, 4 PIN 0.079 SINGLE ROW WURTH, 62000411121

6 12 JP1-JP12 SHUNT, 2mm WURTH, 60800213421

dc2151af

DEMO MANUAL DC2151A

schematic Diagram

D D

C C

B B

A A

UVLO SELECTION

UV1UV2 UV0 UVLO

RISING

000

001

111

10V

000

001

111

12V

14V

16V

18V

UV3

11V

13V

15V

17V

UVLO

FALLING

3V - 19V

2.0V - 4.2V

125mA

* 10mA,

(IF VBB_IN > VFLOAT)

1.8V - 5.0V

DNP DNP

3. INSTALL SHUNTS ON JUMPERS AS SHOWN.

2. ALL CAPACITORS ARE IN MICROFARADS, 0402, 10%, 10V.

1. ALL RESISTORS ARE IN OHMS, 0402, 1%, 1/16W.

NOTES: UNLESS OTHERWISE SPECIFIED

CAUTION: 50mA MAX

OPT

DNP

FLOAT SELECTION AND BATTERY DISCONNECT THRESHOLDS

FLOAT1LBSEL FLOAT0 FLOAT

000

001

111

3.45V

4.0V

4.1V

4.2V

3.45V

4.0V

4.1V

4.2V

CONNECT DISCONNECT

3.05V

2.37V

3.05V

2.86V

3.55V

2.70V

2.04V

2.70V

2.51V

3.20V

50mA

2.0V - 4.2V OPT

OUTPUT VOLTAGE SELECTION

OUT1OUT2 OUT0 VOUT

0 00

001

1 11

1.8V

2.5V

2.8V

3.0V

3.3V

3.6V

4.5V

5.0V

100mA

25mA

150mA

IPK0 ILIM

250mA

5mA

IPK1

50mA

R2 R5

ILM SELECTION

INSTALL

15mA

R5 10mA

IPK2

START

PLACE JP11 IN SHIP POSITION WHEN BOARD IS NOT IN USE.

CHARGE BB_IN

VIN2

VIN3BB_INVIN3

VIN2

VIN3

BB_IN

PGVOUT

EH_ON

VOUT

BB_IN

VIN

FAST_CHRG

SIZE

DATE:

IC NO. REV.

SHEET OF

TITLE:

APPROVALS

PCB DES.

APP ENG.

TECHNOLOGY Fax: (408)434-0507

Milpitas, CA 95035

Phone: (408)432-1900

1630 McCarthy Blvd.

LTC Confidential-For Customer Use Only

CUSTOMER NOTICE

LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A

CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;

HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO

VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL

APPLICATION. COMPONENT SUBSTITUTION AND PRINTED

CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT

PERFORMANCE OR RELIABILITY. CONTACT LINEAR

TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.

THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND

SCHEMATIC

SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.

SCALE = NONE

www.linear.com

DEMO CIRCUIT 2151A

NANOPOWER BUCK - BOOST DC / DC

N/A

LTC3331EUH

2 - 21 - 14

WITH ENERGY HARVESTING BATTERY CHARGER

SIZE

DATE:

IC NO. REV.

SHEET OF

TITLE:

APPROVALS

PCB DES.

APP ENG.

TECHNOLOGY Fax: (408)434-0507

Milpitas, CA 95035

Phone: (408)432-1900

1630 McCarthy Blvd.

LTC Confidential-For Customer Use Only

CUSTOMER NOTICE

LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A

CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;

HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO

VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL

APPLICATION. COMPONENT SUBSTITUTION AND PRINTED

CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT

PERFORMANCE OR RELIABILITY. CONTACT LINEAR

TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.

THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND

SCHEMATIC

SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.

SCALE = NONE

www.linear.com

DEMO CIRCUIT 2151A

NANOPOWER BUCK - BOOST DC / DC

N/A

LTC3331EUH

2 - 21 - 14

WITH ENERGY HARVESTING BATTERY CHARGER

SIZE

DATE:

IC NO. REV.

SHEET OF

TITLE:

APPROVALS

PCB DES.

APP ENG.

TECHNOLOGY Fax: (408)434-0507

Milpitas, CA 95035

Phone: (408)432-1900

1630 McCarthy Blvd.

LTC Confidential-For Customer Use Only

CUSTOMER NOTICE

LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A

CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;

HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO

VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL

APPLICATION. COMPONENT SUBSTITUTION AND PRINTED

CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT

PERFORMANCE OR RELIABILITY. CONTACT LINEAR

TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.

THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND

SCHEMATIC

SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.

SCALE = NONE

www.linear.com

DEMO CIRCUIT 2151A

NANOPOWER BUCK - BOOST DC / DC

N/A

LTC3331EUH

2 - 21 - 14

WITH ENERGY HARVESTING BATTERY CHARGER

REVISION HISTORY

DESCRIPTION DATEAPPROVEDECO REV

JDPRODUCTION FAB- 22 - 21 - 14

REVISION HISTORY

DESCRIPTION DATEAPPROVEDECO REV

JDPRODUCTION FAB- 22 - 21 - 14

REVISION HISTORY

DESCRIPTION DATEAPPROVEDECO REV

JDPRODUCTION FAB- 22 - 21 - 14

JP8

LBSEL

JP8

LBSEL

R5R5

JP4

UV0

JP4

UV0

R10

3.01k

R10

3.01k

22uH

E11

GND

E11

GND

JP5

OUT2

JP5

OUT2

E12

GND

E12

GND

JP11

SHIP

EXT

RUN

SHIP

JP11

SHIP

EXT

RUN

SHIP

4.7uF

0603

6.3V

4.7uF

0603

6.3V

22uH

E10

GND

E10

GND

JP12

OFF

CHARGE

FAST CHARGE

CHARGE

JP12

OFF

CHARGE

FAST CHARGE

CHARGE

AC1

7.5k

AC2

LTC3331EUH

BAL

SCAP 2

VIN2

UV3 4

UV2 5

UV1 6

UV0 7

AC1

AC2

VIN

CAP

SW 12

VOUT 13

SWB 14

SWA 15

BB_IN

IPK0 17

IPK1 18

IPK2 19

BAT_OUT

BAT_IN

LBSEL 22

FLOAT1 23

FLOAT0 24

SHIP

VIN3

CHARGE

PGVOUT

28 EH_ON

OUT0 30

OUT1 31

OUT2 32

GND

BTH2

SMTU2477N-LF

BTH2

SMTU2477N-LF

JP9

FLOAT1

JP9

FLOAT1

BB_IN

JP1

UV3

JP1

UV3

7.5k

100

E14 SCAP

E15

BAT_IN

E15

BAT_IN

R7R7

VIN

0.1uF 10V

JP2

UV2

JP2

UV2

JP10

FLOAT0

JP10

FLOAT0

CHARGE

GND

PB1

WURTH- 434 111 025 826

PB1

WURTH- 434 111 025 826

JP6

OUT1

JP6

OUT1

22uF

1210

25V

22uF

1210

25V

0.1uF

10V

0.1uF

10V

150uF

1210

6.3V

20%

150uF

1210

6.3V

20%

R3R3

BAL

C10

OPT

DMF3R5R5L334M3DTA0

21mm x 14mm

330mF

5.5V

BAL

C10

OPT

DMF3R5R5L334M3DTA0

21mm x 14mm

330mF

5.5V

EH_ON

JP3

UV1

JP3

UV1

0.1uF 10V

PGVOUT

1uF 6.3V

JP7

OUT0

JP7

OUT0

BTH1

SMTU2032-LF

BTH1

SMTU2032-LF

22uF

1206

6.3V

20%

22uF

1206

6.3V

20%

E17

VOUT

E17

VOUT

BAL

90mF

HZ202F

20mm x 15mm

5.5V

BAL

90mF

HZ202F

20mm x 15mm

5.5V

GND

E13

BAL

E13

BAL

E16 GND

Figure18. DC2151A Demo Circuit Schematic, Page 1

dc2151af

DEMO MANUAL DC2151A

Information furnished by Linear Technology Corporation is believed to be accurate and reliable.

However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-

tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.

schematic Diagram

D D

C C

B B

A A

OVERVOLTAGE TOLERANT BUFFERS

TRANSLATE THE HIGH PULL-UP

VOLTAGES FROM THE LTC3330 TO THE

VOUT VOLTAGE DRIVING THE

PROCESSOR I/O BUS, WHICH IS VOUT.

U2, U3, U4 FUNCTION TABLE

III Y

HHLL

210

Y= ( I ) ( I ) + ( I ) ( I )

75.0

56.2

R11 I_CHRG

5mA113

BATTERY CHARGE

CURRENT *

10mA

7.5mA

VOUT VOUT

EH_ON

PGVOUT

VOUT

PGVOUT

EH_ON

VIN

BB_IN

FAST_CHRG

SIZE

DATE:

IC NO. REV.

SHEET OF

TITLE:

APPROVALS

PCB DES.

APP ENG.

TECHNOLOGY Fax: (408)434-0507

Milpitas, CA 95035

Phone: (408)432-1900

1630 McCarthy Blvd.

LTC Confidential-For Customer Use Only

CUSTOMER NOTICE

LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A

CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;

HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO

VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL

APPLICATION. COMPONENT SUBSTITUTION AND PRINTED

CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT

PERFORMANCE OR RELIABILITY. CONTACT LINEAR

TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.

THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND

SCHEMATIC

SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.

SCALE = NONE

www.linear.com

DEMO CIRCUIT 2151A

NANOPOWER BUCK - BOOST DC / DC

N/A

LTC3331EUH

2 - 21 - 14

WITH ENERGY HARVESTING BATTERY CHARGER

SIZE

DATE:

IC NO. REV.

SHEET OF

TITLE:

APPROVALS

PCB DES.

APP ENG.

TECHNOLOGY Fax: (408)434-0507

Milpitas, CA 95035

Phone: (408)432-1900

1630 McCarthy Blvd.

LTC Confidential-For Customer Use Only

CUSTOMER NOTICE

LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A

CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;

HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO

VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL

APPLICATION. COMPONENT SUBSTITUTION AND PRINTED

CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT

PERFORMANCE OR RELIABILITY. CONTACT LINEAR

TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.

THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND

SCHEMATIC

SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.

SCALE = NONE

www.linear.com

DEMO CIRCUIT 2151A

NANOPOWER BUCK - BOOST DC / DC

N/A

LTC3331EUH

2 - 21 - 14

WITH ENERGY HARVESTING BATTERY CHARGER

SIZE

DATE:

IC NO. REV.

SHEET OF

TITLE:

APPROVALS

PCB DES.

APP ENG.

TECHNOLOGY Fax: (408)434-0507

Milpitas, CA 95035

Phone: (408)432-1900

1630 McCarthy Blvd.

LTC Confidential-For Customer Use Only

CUSTOMER NOTICE

LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A

CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;

HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO

VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL

APPLICATION. COMPONENT SUBSTITUTION AND PRINTED

CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT

PERFORMANCE OR RELIABILITY. CONTACT LINEAR

TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.

THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND

SCHEMATIC

SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.

SCALE = NONE

www.linear.com

DEMO CIRCUIT 2151A

NANOPOWER BUCK - BOOST DC / DC

N/A

LTC3331EUH

2 - 21 - 14

WITH ENERGY HARVESTING BATTERY CHARGER

R11

56.2

R11

56.2

NDC7001C

Q1A

NDC7001C

Q1A

R12

1.00Meg

R12

1.00Meg

NC7SZ58P6X

GND

VCC 5

R13

100k

R13

100k

DUST HEADER 2X6

SMH-106-02-L-D-05

DUST HEADER 2X6

SMH-106-02-L-D-05

VSUPPLY 1

GND 3

PGOOD

KEY 5

VBAT

RSVD 7

EHORBAT

I/O 2 9

I/O 1

+5V 11

V+

CMPT3906E

3 2

NC7SZ58P6X

GND

VCC 5

R14

1.00Meg

R14

1.00Meg

CMOSH-3

Q1B

NDC7001C

Q1B

NDC7001C

Figure19. DC2151A Demo Circuit Schematic, Page 2

dc2151af

DEMO MANUAL DC2151A

Linear Technology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

(408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com

 LINEAR TECHNOLOGY CORPORATION 2014

LT 0614 • PRINTED IN USA

DEMONSTRATION BOARD IMPORTANT NOTICE

Linear Technology Corporation (LT C ) provides the enclosed product(s) under the following AS IS conditions:

This demonstration board (DEMO BOARD) kit being sold or provided by Linear Technology is intended for use for ENGINEERING DEVELOPMENT

OR EVALUATION PURPOSES ONLY and is not provided by LT C for commercial use. As such, the DEMO BOARD herein may not be complete

in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including but not limited to product safety

measures typically found in finished commercial goods. As a prototype, this product does not fall within the scope of the European Union

directive on electromagnetic compatibility and therefore may or may not meet the technical requirements of the directive, or other regulations.

If this evaluation kit does not meet the specifications recited in the DEMO BOARD manual the kit may be returned within 30 days from the date

of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE WARRANTY MADE BY THE SELLER TO BUYER AND IS IN LIEU

OF ALL OTHER WARRANTIES, EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS

FOR ANY PARTICULAR PURPOSE. EXCEPT TO THE EXTENT OF THIS INDEMNITY, NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR

ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES.

The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user releases LT C from all claims

arising from the handling or use of the goods. Due to the open construction of the product, it is the user’s responsibility to take any and all

appropriate precautions with regard to electrostatic discharge. Also be aware that the products herein may not be regulatory compliant or

agency certified (FCC, UL, CE, etc.).

No License is granted under any patent right or other intellectual property whatsoever. LT C assumes no liability for applications assistance,

customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind.

LT C currently services a variety of customers for products around the world, and therefore this transaction is not exclusive.

Please read the DEMO BOARD manual prior to handling the product. Persons handling this product must have electronics training and

observe good laboratory practice standards. Common sense is encouraged.

This notice contains important safety information about temperatures and voltages. For further safety concerns, please contact a LT C applica-

tion engineer.

Mailing Address:

Linear Technology

1630 McCarthy Blvd.

Milpitas, CA 95035