Voltage Regulators

Owned by Andrew Fearing
Last updated: Nov 08, 2021
3 min read

This page describes the performance of different passive components with the voltage regulators on Sulu and Spock PCBs.

Introduction

The Spock and Sulu PCBs have voltage regulators so that a 3 V battery can power SCuM, which takes up to 2 V. The voltage regulators have been noisier and less efficient than expected.

Component selection

 

Friendly name

Model number

Designator

Notes

Datasheet

spock 10 uF cap

GRJ155R60J106ME11D

C_1.1_IN1, C_1.1_OUT1, C_1.8_IN2 , C_1.8_OUT2

 

 

old 10 uF cap

CL05A106MP8NUB8

C_1.1_IN1, C_1.8_IN2

 

 

new 10 uF cap

GRM155R60J106ME15D

C_1.1_IN1, C_1.1_OUT1, C_1.8_IN2 , C_1.8_OUT2

Recommended on datasheet

 

100 uF cap

GRM21BR60E107ME15L

C_1.1_OUT1, C_1.8_OUT2

 

 

old inductor

MLZ1005M2R2WT000

L1, L2

 

https://product.tdk.com/system/files/dam/doc/product/inductor/inductor/smd/catalog/inductor_commercial_decoupling_mlz1005_en.pdf

new inductor

74438343022

L1, L2

Recommended on datasheet

https://www.we-online.com/katalog/datasheet/74438343022.pdf

1.1V DC-DC

S-85S1AB11-I6T1U

U3

 

https://www.ablic.com/en/doc/datasheet/switching_regulator/S85S1A_E.pdf

1.8V DC-DC

S-85S1AB18-I6T1U

U2

 

https://www.ablic.com/en/doc/datasheet/switching_regulator/S85S1A_E.pdf

Note that the 1.1V DC-DC converters were missing so 1.0V DC-DC converters were used as a substitute.

Boards

Friendly name

Designator

Board

L1, L2

C_1.x_INy

C_1.x_OUTy

VBAT converter

VDDD converter

Recommended components

DC1

Sulu v1.0

74438343022

GRM155R60J106ME15D

GRM155R60J106ME15D

S-85S1AB18-I6T1U

S-85S1AB10-I6T1U

Spock components

DC2

Sulu v1.0

MLZ1005M2R2WT000

GRJ155R60J106ME11D

GRJ155R60J106ME11D

S-85S1AB18-I6T1U

S-85S1AB10-I6T1U

 

L6/L7

Sulu v1.0

MLZ1005M2R2WT000

CL05A106MP8NUB8

GRM21BR60E107ME15L

S-85S1AB18-I6T1U

S-85S1AB11-I6T1U

Figures

Efficiency of S-85S1AB18-I6T1U from datasheet
Measured efficiency of S-85S1AB18-I6T1U

 

Waveforms

DC1

DC2

 

L6

 

I-V measurements

Board

V_ext (V)

R_load (k Ohm)

R_ext (k Ohm)

I_ext (mA)

V_bat (V)

I_bat (mA)

P_ext (mW)

P_bat (mW)

P_bat/P_ext (%)

DC1

3

11.94

0

1.389

1.791

0.1506

4.167

0.269725

6%

DC1

3

5.25

0

1.502

1.765

0.3365

4.506

0.593923

13%

DC1

3

1.194

0

2.304

1.783

1.494

6.912

2.663802

39%

DC2

3

11.94

0

1.781

1.799

0.1509

5.343

0.271469

5%

DC2

3

5.25

0

1.951

1.8

0.3431

5.853

0.61758

11%

DC2

3

1.194

0

2.95

1.779

1.483

8.850

2.638257

30%

L6

3

11.94

0

1.88

1.757

0.147

5.640

0.258279

5%

L6

3

5.25

0

2.1

1.821

0.347

6.300

0.631887

10%

L6

3

1.194

0

3.15

1.814

1.52

9.450

2.75728

29%

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