Joulescope JS220+ Datasheet#

The Joulescope™ JS220+ is a limited-edition, performance-enhanced version of the Joulescope JS220. The JS220+ achieves ±1 nanoamp accuracy with exceptional temperature stability, all while providing the same best-in-class high-dynamic current range measurement as the standard JS220.

The Joulescope JS220+ User’s Guide describes the JS220+ improvements, and the Joulescope JS220 User’s Guide describes how to use the instrument. The specification values are also available as js220plus.yaml, which holds the differences from js220.yaml.

The JS220+ specifications are the same as the JS220, except for the current measurement, voltage measurement and parasitic effects specifications. Resolution is given for 10 kHz measurement bandwidth (20 ksps). The JS220+ includes a safety banana jack front panel rather than binding posts.

Absolute maximum ratings#

	Min	Max	Unit
USB voltage	-0.3	6	V
Max voltage applied between any port (Current +, Current -, Voltage +, Voltage -)	-20	20	V
Max voltage to USB ground from any port (Current +, Current -, Voltage +, Voltage -)	-48	48	V
Input current (powered, burst)	-10	10	A
Input current (powered, sustained)	-3	3	A
Input current (unpowered)	N/A (off)	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#

Instrument only#

	Typical	Unit
Weight	190	grams
Width	99	mm
Length (including binding posts and BNC connector)	126	mm
Height	28	mm

Complete product kit#

	Typical	Unit
Weight	510	grams
Width	190	mm
Length	200	mm
Height	60	mm

Recommended operating conditions#

	Test condition	Min	Typical	Max	Unit
Operating temperature		10		40	°C
USB supply voltage		4.5	5.0	5.5	V
USB supply current				500	mA
Voltage applied across Voltage + and Voltage -		-14.5		14.5	V
Voltage applied across Current + and Current -	Current range off	-15		15	V
Input current	continuous	-3		3	A
Input current pulse	< 50 milliseconds, < 3A average	-10¹		10¹	A
Input current pulse	< 250 milliseconds, < 3A average	-5¹		5¹	A

Suitable for handling inrush currents when connecting capacitive loads.

Specification conditions#

Temperature	23 °C ± 10 °C
Humidity	20% to 80% RH, non-condensing
Calibration interval	1 year¹

Recommended to comply with industry-standard practices, but the Joulescope JS220 is designed not to need recalibration.

Current measurement specifications#

Range	Accuracy	Resolution	Impedance	Guaranteed
10 A (> 2 A)¹	±0.25% ±1.5 mA	350 µA	0.01 Ω	±9.7 A
10 A (≤ 2 A)	±0.1% ±300 µA	75 µA	0.01 Ω	±2.05 A
180 mA	±0.1% ±30 µA	6.5 µA	0.11 Ω	±185 mA
18 mA	±0.1% ±3.0 µA	650 nA	1.11 Ω	±18.5 mA
1.8 mA	±0.1% ±300 nA	65 nA	11.1 Ω	±1.85 mA
180 µA	±0.1% ±30 nA	6.5 nA	111 Ω	±185 µA
18 µA	±0.1% ±3 nA²	0.65 nA	1111 Ω	±18.5 µA

Max 3 A sustained. See the recommended operating conditions for higher current durations.
±1.0 nA for ±5 °C over 24 hours with trim offset calibration.

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.

The JS220 is sensitive to RF radiation which induces real current in test setups. When tested with EN61326-1 and 3 V RMS/m, the JS220 measured up to 10 µA (observed, not guaranteed) of current at several frequencies. The exact frequency susceptibility varies with cable length and configuration.

Voltage measurement specifications#

Range	Accuracy	Resolution	Guaranteed
15 V	±0.1% ±1 mV	500 µV	±14.5 V
2 V	±0.1% ±150 µV	75 µV	±2.2 V

The JS220 is sensitive to RF radiation which induces real voltages in test setups. When tested with EN61326-1 and 3 V RMS/m, the JS220 error increased by 10 mV (observed, not guaranteed) at several frequencies. The exact frequency susceptibility varies with cable length and configuration.

General specifications#

	Test condition	Min	Typical	Max	Unit
Sampling frequency	25 °C		2000000		sps
Sampling frequency	25 °C	-25		25	ppm
Measurement bandwidth	-3 dB	280	310	350	kHz
Front panel insertions				100

Parasitic effects specifications#

	Test condition	Min	Typical	Max	Unit
Current leakage (Voltage + to -)	25 °C, ±3.3V			200	pA
Current leakage (Voltage + to -)	25 °C, ±5V			200	pA
Current leakage (Voltage + to -)	25 °C, ±14V			300	pA
Shunt resistor voltage, max	-2 to 2 A, static		20	21	mV
Burden voltage (Current + to -)	1 A, banana jacks	0	25	35	mV
Burden voltage (Current + to -)	Shunt resistor, < ±2 A			±20	mV
Shunt switching time	Over-range, < 200 ns rise time	0	1.0	1.5	µs
Measurement gap following a current range switch				0	µs
Input bias current Voltage+ & -	25 °C		±5	±20	pA
Input bias current, Current + & -	25 °C, 18 µA current range		±60	±600	pA

Software-controlled fuse specifications#

	Test condition	Typical	Max	Unit
Current leakage (Current + to -)	25 °C, 3.3V	±5		nA
Current leakage (Current + to -)	25 °C, 5V	±7		nA
Current leakage (Current + to -)	25 °C, 15V	±28	±5000	nA
Max fuse engage	5 A	0.293		s
Max fuse engage	10 A	0.050		s

General purpose inputs and outputs#

	Test condition	Min	Typical	Max	Unit
Internal 3.3V reference		3.135	3.3	3.465	V
External reference	Vref < (VUSB - 0.5 V)	Vref - 0.1	Vref	Vref + 0.1	V
Input leakage per pin	25 °C			±10	nA
Input leakage per pin				±100	nA
Output voltage high	-100 µA	Vcco - 0.1			V
Output impedance	10 mA	45	50	80	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 TI TPD4E1U06 for ESD protection.