Joulescope JS110 Datasheet#

The Joulescope™ JS110 is a precision DC energy analyzer. It measures current and voltage, then computes power and energy. It combines high-speed sampling and rapid dynamic current range switching to provide accurate and seamless current and energy measurements, even for devices with rapidly varying current consumption.

  • -1V to 15V voltage range

  • -1A to 3A current range, continuous

  • Up to 10A current pulses (<10 ms, < 3A average per second)

  • Down to 1.5 nA resolution, equivalent to 32-bits of dynamic range

  • Synchronously measures voltage and current at 2 million samples per second, 14-bit

  • 250 kHz bandwidth

  • Rapid 1 µs switching between shunt resistors for seamless dynamic current measurement

  • Computes power, total energy, and charge

  • Operates with minimal voltage disturbance between IN and OUT ports

  • Up to ±48V common-mode voltage between USB ground and IN-, IN+, OUT+, and OUT-

  • 2 general-purpose inputs and 2 general-purpose outputs

  • Programmable on/off for power cycling the target device and measuring inrush currents

  • USB 2.0 high-speed host connectivity

  • Host software support for Microsoft® Windows®, Apple® Mac® OS X®, and Linux®

  • Host software provides real-time graphs of current, voltage, and power over time

  • Host software is open source and available on GitHub

  • Swappable front panel with open-source designs on GitHub

  • Firmware upgradable

The Joulescope JS110 User’s Guide describes how to use the instrument. The specification values are also available as js110.yaml.

Absolute maximum ratings#

Min

Max

Unit

USB voltage

-0.3

6

V

Max voltage applied between IN+ to IN-

-20

20

V

Max voltage applied between OUT+ to OUT-

-20

20

V

Max voltage to USB ground (IN+, IN-, OUT+, OUT-)

-48

48

V

Input current (powered, burst)

-10

10

A

Input current (powered, sustained)

-3

3

A

Input current (unpowered)

-0.5

N/A (off)

A

Storage temperature

-40

80

°C

Operating temperature

0

50

°C

Relative humidity (non-condensing)

0

95

%

Altitude from sea level

-100

2500

m

Max voltage applied to GPI relative to USB ground

-10

10

V

Mechanical#

Typical

Unit

Weight

217

grams

Width

81

mm

Length (including banana jack front panel)

150

mm

Height

33

mm

Specification conditions#

Temperature

23 °C ± 10 °C

Humidity

20% to 80% RH, non-condensing

Calibration interval

1 year1

  1. Recommended to comply with industry-standard practices, but Joulescope is designed not to need recalibration.

Current measurement specifications#

Range

Accuracy

Resolution

Impedance

Bandwidth

10 A1

±0.3% ±7 mA

1 mA

0.01 Ω

250 kHz

2 A

±0.3% ±1.50 mA

175 µA

0.01 Ω

250 kHz

180 mA

±0.3% ±150 µA

15 µA

0.11 Ω

250 kHz

18 mA

±0.25% ±15 µA

1.5 µA

1.11 Ω

250 kHz

1.8 mA

±0.25% ±1.5 µA

150 nA

11.1 Ω

180 kHz

180 µA

±0.25% ±150 nA

15 nA

111 Ω

70 kHz

18 µA

±0.25% ±30 nA

1.5 nA

1111 Ω

15 kHz

  1. Joulescope is designed for 3 A sustained. See the recommended operating conditions for maximum durations for higher currents.

Test current measurement bandwidth by varying the effective load impedance. Due to load capacitance, altering the source voltage is not a valid method of testing current bandwidth.

Voltage measurement specifications#

Range

Accuracy

Resolution

Impedance

Bandwidth

15 V

±0.1% ±11 mV

1.2 mV

-

250 kHz

5 V

±0.1% ±3.5 mV

400 µV

-

250 kHz

General specifications#

Test condition

Min

Typical

Max

Unit

Sampling frequency

25 °C

2000000

sps

Sampling frequency

25 °C

-20

20

ppm

Front panel insertions

100

Parasitic effects specifications#

Test condition

Min

Typical

Max

Unit

Current leakage (IN+ to IN-)

25 °C, +3.3V

2

nA

Current leakage (IN+ to IN-)

25 °C, +5V

2

nA

Current leakage (IN+ to IN-)

25 °C, +15V

3

nA

Shunt resistor voltage, max

0 to 2 A, static

20

21

mV

Burden voltage (IN+ to OUT+)

< 1 A, banana jacks

0

25

30

mV

Burden voltage (OUT- to IN-)

< 1 A, banana jacks

0

3

8

mV

Shunt switching time

Over-range, < 100 ns rise time

0

0.8

1.2

µs

Over-range settling time

0

2

5

µs

Under-range settling time

0

2

5

µs

Software-controlled fuse specifications#

Test condition

Min

Typical

Max

Unit

Current leakage (IN+ to OUT+)

25 °C, 3.3V

5

nA

Current leakage (IN+ to OUT+)

25 °C, 5V

7

nA

Current leakage (IN+ to OUT+)

25 °C, 15V

28

5000

nA

General purpose inputs and outputs#

Test condition

Min

Typical

Max

Unit

Programmable logic level voltage

1.8

VUSB - 0.2

V

Input leakage per pin

25 °C

±1

µA

Input leakage per pin

±2

µA

Output voltage high

-100 µA

Vcco - 0.1

V

Output voltage high

-4 mA @ 1.65 V

1.2

V

Output voltage high

-8 mA @ 2.3 V

1.9

V

Output voltage high

-24 mA @ 3 V

2.4

V

Output voltage high

-32 mA @ 4.5 V

3.8

V

Output voltage low

100 µA

0.1

V

Output voltage low

4 mA @ 1.65 V

0.45

V

Output voltage low

8 mA @ 2.3 V

0.3

V

Output voltage low

24 mA @ 3 V

0.55

V

Output voltage low

32 mA @ 4.5 V

0.55

V

Output impedance

10 mA

90

100

110

Ω

GPI sample rate

2

MSPS

Continuous output current

Per pin

±50

mA

Total power dissipation

Over output impedance

0.25

W

The Joulescope uses the TI SN74LVC2T45 for both the GPIs and GPOs. See the SN74LVC2T45 datasheet for more information. Both the GPIs and GPOs are protected with the Vishay VEMI45AA-HNH, which is an EMI filter with ESD protection. The VEMI45AA is a pi filter with 100 Ohm resistance and capacitance between 29 pF and 60 pF.

GPIO supply#

Min

Typical

Max

Unit

+5V output

4.4

VBUS - 0.1

5.5

V

Current

100

mA

Output impedance

1

Ω