Nordic nPM1100 EK User manual

nPM1100 EK Hardware
v0.8.0
User Guide
4477_012 / 2021-05-27

Contents
Revision history.................................. iii
1Introduction................................... 4
2Minimum requirements............................ 5
3Kit content.................................... 6
4Hardware description.............................. 7
4.1 Hardware figures .................................7
4.2 Block diagram .................................. 8
4.3 Power supply .................................. 8
4.4 LEDs ...................................... 9
4.5 Switches .................................... 9
4.5.1 Charge voltage termination .......................... 9
4.5.2 Charge current limit ............................. 10
4.5.3 Output voltage configuration ......................... 10
4.5.4 Buck regulator mode ............................. 11
4.5.5 VBUS current limit .............................. 11
4.6 Buttons .................................... 11
4.6.1 Ship mode activation .............................11
4.6.2 Ship mode disabling ............................. 12
4.7 Solder bridge configuration ............................ 12
4.8 NTC configuration ................................ 12
5Measuring current............................... 13
5.1 Preparing the nPM1100 EK ............................ 13
5.1.1 Preparing for VBUS current measurements ....................14
5.1.2 Preparing for VBAT current measurements .................... 14
5.1.3 Preparing for VOUTB current measurements ................... 14
5.2 Using an oscilloscope for current profile measurement ................ 15
5.3 Using an ampere meter for current measurements .................. 16
5.4 Using the Power Profiler Kit II for current measurements ................16
5.4.1 Measuring VBUS current ........................... 16
5.4.2 Measuring VBAT current ........................... 17
5.4.3 Measuring VOUTB current .......................... 18
Glossary ..................................... 20
Acronyms and abbreviations............................21
Recommended reading.............................. 22
Legal notices................................... 23
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Revision history
Date Description
2021-05-27 First release
4477_012 iii

1Introduction
The nPM1100 EK is a hardware platform used to evaluate the nPM1100 Power Management Integrated
Circuit (PMIC).
The key features of the Evaluation Kit (EK) are:
• nPM1100 EK PMIC
• Lithium-ion/lithium-polymer USB battery charger
• High efficiency step-down buck regulator
• Power supply from USB, pins, or battery
• DIP Switches to set:
• Step-down regulator output voltage
• Charge current
• Charge termination voltage
• USB current limit
• BUCK operating mode
• Buttons for entering/leaving Ship mode
• Headers for connecting to configuration pins
• Pins for measuring current flow
For access to hardware schematics and layout files, see nPM1100 EK product page.
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2Minimum requirements
Before you start, check that you have the required hardware.
Hardware requirements
• Power supply, USB or connector
• Micro-USB 2.0 cable
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3Kit content
The nPM1100 EK consists of hardware, reference design files, and documentation.
The EK only comes with the board. You need to provide your own Micro-USB cable.
Figure 1: nPM1100 EK
Hardware files
The hardware design files including schematics, PCB layout files, bill of materials, and Gerber files for the
nPM1100 EK are available on the nPM1100 EK product page.
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4Hardware description
The nPM1100 EK allows full flexibility for configuration of the nPM1100 PMIC without having to make
any hardware modifications. The EK supports Primary Detection of the USB port type based on the USB
Battery Charging Specification.
Alternatively, the current limitation can be controlled manually by a switch. The current limitation switch
can only override from a 100–500 mA limit for a Standard Downstream Port (SDP) detection. It cannot
override or limit a 500 mA Dedicated Charging Port (DCP) down to 100 mA.
4.1 Hardware figures
The nPM1100 EK hardware drawings show both sides of the EK.
Figure 2: nPM1100 EK front view
Figure 3: nPM1100 EK back view
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Hardware description
4.2 Block diagram
The block diagram illustrates the nPM1100 EK functional architecture.
VSYS
ICHG
MODE
ISET
VOUTBSET
SHPACT
SHPHLD
nPM1100
VOUTB
ERR
CHG
Battery
USB
VTERM NTC
Figure 4: nPM1100 EK block diagram
4.3 Power supply
The nPM1100 EK has a flexible and configurable power supply system to allow testing with different power
sources and to facilitate accurate power measurements.
The power options are:
• USB connector J2 (5.0 V)
• VBUS P8 pin 1 (4.5–6.7 V)
• Connectors for Li-ion/Li-poly batteries P2, P3, P6 or, P4 pin 1 (2.5–4.2 V)
Note: Use only one connector at a time.
Use the USB connector or the VBUS pin for powering the system and delivering power when charging. The
nPM1100 PMIC will pull current from the battery if no external power source is connected to J2/P4.
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Hardware description
Figure 5: Power supply options
4.4 LEDs
The nPM1100 EK has two LEDs for visualizing the status of the nPM1100 battery charger. Both can be
disconnected for power consumption measurements.
VSYS
ERR
CHG
SB1 LD1 L0603G
LD2 L0603GSB2
VSYS
Figure 6: LED schematic
Part Function Solder bridge
LD1 Error indication, ERR SB1, cut to disconnect LD1
LD2 Charge active indication, CHG SB2, cut to disconnect LD2
Table 1: LED connection
4.5 Switches
The nPM1100 EK has several switches to configure the nPM1100 device. All switches have series resistors
to allow the onboard switches to be overridden by external input.
4.5.1 Charge voltage termination
SW4 controls the charge voltage termination.
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Hardware description
Switch Function Parameter controlled
SW4 Charge voltage termination VTERMSET
Table 2: Charge voltage termination parameters
4.5.2 Charge current limit
SW7 controls the maximum charge current limit.
Switch Function Parameter controlled
SW7 Charge current limit ICHG
Table 3: Charge current limit parameters
SW7 is a 5-pole dip switch that can select the five defined current limits in the following table. This is
done by setting the resistance from ICHG to GND. Closing multiple switches simultaneously decreases
the resistance and increases the current limit. The user configured current limit can be set by leaving all
switches open and selecting an appropriate R12 value.
ICHG Charge current R_ICHG
1 400 mA 0 Ω
2 250 mA 1.0 kΩ
3 150 mA 2.7 kΩ
4 50 mA 12 kΩ
5 20 mA 27 kΩ
Table 4: SW7 current limits
4.5.3 Output voltage configuration
SW6 controls the nPM1100 step-down regulator output voltage.
Switch Function Parameter controlled
SW6A VOUTBSET1
SW6B
Output Voltage configuration
VOUTBSET0
Table 5: Output voltage configuration parameters
SW6 is a 2-pole dip switch used to support four defined output voltage levels.
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Hardware description
VOUTBSET1/SW6A VOUTBSET1/SW6B VOUTB
GND GND 1.8 V
GND VSYS 2.1 V
VSYS GND 2.7 V
VSYS VSYS 3.0 V
Table 6: SW6 output voltage levels
4.5.4 Buck regulator mode
SW1 controls the operating mode of the buck regulator.
Switch Function Parameter controlled
SW1 Buck regulator mode control MODE
Table 7: Buck regulator configuration parameters
The nPM1100 buck regulator supports two operating modes and SW1 selects which mode to use.
SW1 Buck mode
GND Automatic
VSYS PWM mode
Table 8: Buck regulator operating modes
4.5.5 VBUS current limit
SW3 controls the VBUS current limit.
Switch Function Parameter controlled
SW3 VBUS current limit configuration ISET
Table 9: VBUS current limit parameters
ISET can override the 100 mA current limit when a USB cable is not used or a USB SDP is detected.
4.6 Buttons
The nPM1100 EK has two buttons used to control the device. All buttons have series resistors to allow
external input to override the onboard buttons.
4.6.1 Ship mode activation
Activate ship mode by pushing SW4.
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Hardware description
Button Function Parameter controlled
SW2 Ship mode activation SHPACT
Table 10: Ship mode activation parameters
4.6.2 Ship mode disabling
Disable ship mode by pushing SW5.
Button Function Parameter controlled
SW5 Ship mode disabling SHPHLD
Table 11: Ship mode disabling parameters
4.7 Solder bridge configuration
The nPM1100 EK has multiple solder bridges for enabling or disabling functionality on the EK. Changes to
the solder bridges are not needed for normal use of the EK.
The following table is a complete overview of the solder bridges on the nPM1100 EK.
Solder bridge Default Function
SB1 Closed Cut to disconnect ERR LED
SB2 Closed Cut to disconnect CHG LED
SB3 Closed Cut to allow measurement of VBUS current
SB4 Closed Cut to allow measurement of VBAT current
Table 12: Solder bridge configuration
4.8 NTC configuration
The nPM1100 PMIC implements thermal protection based on battery temperature via the NTC pin.
When using a battery pack with an integrated thermistor, battery connector P2 should be used and header
P5 should be left unconnected.
When using a battery pack without an integrated thermistor or when using connector P3, P6, or P8 pin 2,
a 10 kΩ onboard resistor can be used instead of a thermistor by shorting P5 pin 2 and pin 3.
Optionally, a thermistor can also be mounted onboard via R19 footprint. P5 pins 1 and 2 must be shorted
together to connect the thermistor.
If there is no NTC in the battery pack and the P5 header is not adjusted, charging will not occur and the
CHG LED will not light up.
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5Measuring current
The nPM1100 EK supports the monitoring of current flowing into the PMIC, to and from the battery, and
into the external application .
Note: The battery charger includes automatic trickle charge control which introduces restrictions
on what current measurement instruments can be used with VBAT.
Current can be measured using various test instruments. Some examples of test equipment are the
following:
• Power analyzer, uni/bidirectional capability
• Oscilloscope, bidirectional capability
• Ampere meter, bidirectional capability
• Power Profiler Kit II (PPK2), unidirectional capability
The nPM1100 PMIC primary power supply is from VBUS. The secondary power supply as well as charger
output is VBAT.
The nPM1100 PMIC primary output is VOUTB.
Component VBUS VBAT VOUTB
Measurement connector P8, pin 1 P4, pins 1 and 2 P4, pin 3
Solder bridge SB3 SB4
Series resistor R1 R20
Series resistor range <100 mΩ <100 mΩ
Directionality Unidirectional Bidirectional Unidirectional
Table 13: Components for current measurement
For more information on current measurement, see the tutorial Current measurement guide:
Introduction.
5.1 Preparing the nPM1100 EK
To measure current, you must first prepare the EK.
The nPM1100 EK is configured to work directly without changes when powering up. To enable current
measurement on an output, cut the associated solder bridge.
Changes are not needed when using the PPK2.
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Measuring current
Figure 7: Prepare the EK for current measurements
5.1.1 Preparing for VBUS current measurements
You can prepare the EK for measuring VBUS current based on different scenarios.
To prepare the EK:
• To use P1 as a probe-point for performing current measurement on VBUS, cut the PCB track shorting
solder bridge SB3.
• To use an oscilloscope for measurements, mount a series resistor on R1. The recommended resistance
value is 100 mΩ.
To restore normal kit functionality after measurements, solder SB3, add a 0 Ω resistor on R1 or apply a
jumper on P1.
5.1.2 Preparing for VBAT current measurements
You can prepare the EK for measuring VBAT current based on different scenarios.
To prepare the EK:
• To use P4 as a probe-point for performing current measurement on VBAT, cut the PCB track shorting
solder bridge SB4.
• Use bidirectional capable current measurement equipment because current flow on VBAT is
bidirectional.
• The automatic trickle charge feature requires the impedance of the measurement circuit to be
constant and less than 100 mΩ. Autoranging multimeters may automatically change resistance
depending on range, this may lead to the error state of the charger to trigger.
• Mount the series resistor on R20 to use an oscilloscope for measurements. The recommended value is
100 mΩ or lower.
To restore normal kit function after measurement, solder SB4, add a 0 Ω resistor on R20, or apply a jumper
across pins 1 and 2 on P4.
5.1.3 Preparing for VOUTB current measurements
Connect the measurement circuit between VOUTB on P4 pin 3 and the external load.
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Measuring current
5.2 Using an oscilloscope for current profile
measurement
Battery current profile can be measured using an oscilloscope with a differential probe across a shunt
resistor. The voltage drop across the resistor will be proportional to the current flow. An oscilloscope can
then measure the average current over a given time and capture the current profile.
Make sure you have prepared the EK as described in Preparing the nPM1100 EK on page 13.
1. Mount a shunt resistor within the acceptable range on the series resistor footprint for the signal of
interest.
2. Connect an oscilloscope in differential mode or a similar mode with two probes on the pins of the
measurement connector for the signal of interest.
Note: Table 13: Components for current measurement on page 13 provides more
information on the components used for the steps above.
3. Calculate or plot the instantaneous current from the voltage drop across the resistor by taking the
difference of the voltages measured on the two probes. The voltage drop will be proportional to the
current. For instance, a 100 mΩ resistor will cause a 0.1 mV drop for each 1 mA drawn by the circuit
being measured.
The plotted voltage drop can be used to calculate the current at a given point in time. The current can
then be averaged or integrated to analyze current and energy consumption over a period.
Figure 8: VBAT current measurement with an oscilloscope
Some tips to reduce noise:
• Use X1 passive probes
• Enable averaging mode to reduce random noise
• Enable high resolution function if available
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Measuring current
Use a minimum of 200 kSa/s (one sample every 5 µs) to get the correct average current measurement.
5.3 Using an ampere meter for current measurements
An ampere meter can measure the average current flow. This method monitors the current flow by placing
the ampere meter in series with the circuit of interest.
Make sure you have prepared the EK as described in Preparing the nPM1100 EK on page 13.
Connect an ampere meter between the measurement connector for the signal of interest. See Table 13:
Components for current measurement on page 13 for details.
Figure 9: VBUS current measurement with an ampere meter
5.4 Using the Power Profiler Kit II for current
measurements
The average and instantaneous current flow can be measured using the PPK2. This is done either with the
PPK2 as the power supply for the nPM1100 EK or in series between the nPM1100 EK and the load.
Note: For more information on the PPK2, see the Power Profiler Kit User Guide.
5.4.1 Measuring VBUS current
The PPK2 is operated in Source meter mode for this configuration.
1. Connect the PPK2 to the nPM1100 EK with the 4-pin measurement cable using the following pins:
• PPK2 GND to nPM1100 EK GND on either P7 or P8 (pin 9)
• PPK2 VOUT to nPM1100 EK VBUS on P8 (pin 1)
2. Connect the load (nRF5340 DK in this example) to VOUTB (pin 3) and GND (pin 4) on nPM1100 EK P4.
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Measuring current
3. Connect the PPK2 to a computer using a USB cable.
4. Start the Power Profiler app.
5. Select your PPK2.
6. Select Source meter as the mode.
7. Set the supply voltage to value between 4.5 - 5.0 V.
8. Toggle Enable power output to power the nPM1100 EK.
9. Click Start.
5.4.2 Measuring VBAT current
The PPK2 is operated in Source meter mode for this configuration.
1. Connect the PPK2 to the nPM1100 EK with the 4-pin measurement cable using the following pins:
• PPK2 GND to nPM1100 EK GND on either P7 or P8 (pin 9)
• PPK2 VOUT to nPM1100 EK VBAT_HF on P4 (pin 2)
2. Connect the load (nRF5340 DK in this example) to VOUTB (pin 3) and GND (pin 4) on nPM1100 EK P4.
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Measuring current
3. Connect the PPK2 to a computer using a USB cable.
4. Start the Power Profiler app.
5. Select your PPK2.
6. Select Source meter as the mode.
7. Set the supply voltage to value between 3.0 - 4.35 V.
8. Toggle Enable power output to power the nPM1100 EK.
9. Click Start.
5.4.3 Measuring VOUTB current
The PPK2 is operated in Ampere meter mode for this configuration.
1. Connect the PPK2 to the nPM1100 EK with a 4-pin measurement cable using the following pins:
• PPK2 GND to nPM1100 EK pin 4 on P4
• PPK2 VIN to nPM1100 EK pin 3 on P4
• PPK2 VOUT to Development Kit (DK) External supply
• PPK2 GND to DK External supply
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Measuring current
2. Connect the PPK2 to a computer using a USB cable.
3. Connect the nPM1100 EK to a USB power source using a USB cable.
4. Start the Power Profiler app.
5. Select your PPK2.
6. Select Ampere meter as the mode.
7. Toggle Enable power output to power the target device (nRF5340 DK in this example).
8. Click Start.
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Glossary
Dedicated Charging Port (DCP)
A downstream port on a device that outputs power through a USB connector but is not capable of
enumerating a downstream device.
Development Kit (DK)
A development platform used for application development.
Evaluation Kit (EK)
A platform used to evaluate different development platforms.
Power Management Integrated Circuit (PMIC)
A chip used for various functions related to power management.
Standard Downstream Port (SDP)
A downstream port on a device that complies with the USB 2.0 definition of a host or hub.
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