DEMO MANUAL DC2156A LTC2946 2 Wide Range I C Power, Charge and Energy Meter Description Demonstration circuit 2156A features the LTC 2946 The demo board features nested pads for a range of sense rail-to-rail system monitor that measures current, volt- resistor package sizes to support currents of up to 15A age, power, energy and charge. It features an operating range. The full scale sense voltage is 102.4mV. A 20m range of 2.7V to 100V and includes a shunt regulator for sense resistor is populated on the board for 5.12A full operation from supplies above 100V to allow flexibility in scale. The full scale current can be changed by populating the selection of input supply. The current measurement RSNS accordingly. range of 0V to 100V is independent of the input supply. The DC2156A was designed to be connected to the DC590 An onboard, 0.4% accurate, 12-bit ADC measures load and controlled through the QuikEval suite of software. All current, input voltage and an auxiliary external voltage. thresholds can be set and ADC registers read back through A 24-bit power value is generated by digitally multiplying the QuikEval interface, which provides a convenient way the measured 12-bit load current and input voltage data. to evaluate the LTC2946. Energy and charge data are generated by integrating power L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and and current. Minimum and maximum values are stored QuikEval and Linduino are trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. and an overrange alert with programmable thresholds minimizes the need for software polling. Data is reported 2 via a standard I C interface. Shutdown mode reduces power consumption to 20A. 4V + TO LOAD 75V TO DC590 OR DC2026 Figure 1. Typical Application Circuit dc2156af 1DEMO MANUAL DC2156A Dc 2156A p An D Jumper Definitions Jumper Se TTing S Vpu : Pull Up Voltage for the LEDs. Derived from a 5V isolated supply on the DC590. It powers the GPIO LEDs Jp1: Selects the V source. It can be set to V , INTV DD IN CC on the board. If a DC590 is not used and the DC2156A or EXTV (which requires a voltage to be present at the DD is operated independently, a 2.5V to 5V supply must be EXTV turret.) Please see Powering the DC2156A section DD provided here, in order for the LEDs to work. 5V from for examples of how these different settings are used. DC590 and the VPU turret input voltage are diode-ORed by 2 Jp2 (ADr 0), Jp3(ADr 1): Selects the I C slave address D6 to preclude back feeding from one source to the other. of the LTC2946. Any changes here should also be made + SenSe : Supply Voltage and Current Sense Input. Used inside of QuikEval for communications to persist. By as a Kelvin input for the internal current sense amplifier. default, both jumpers are set to LOW which corresponds The voltage at this pin is also monitored by the onboard to an address of 0xDE. ADC with a full-scale input range of 102.4V. The full scale current sense voltage is 102.4mV. Turre TS AnD BAnAnA JACkS SenSe : Current Sense Input. An external 20m sense Signal connections are made via the row of turret posts + resistor (RSNS) is connected between SENSE and SENSE along the edges of the board. to measure a full scale current of 5.12A. See Hardware Setup section for details. gn D: (5 turrets, 2 banana jacks) These turrets are con- nected directly to the ground planes. 2 SCL: I C Clock input. V : Main Supply Input. The LTC2946 measures the cur- 2 in SDA/SDAi: I C Data Input. Connected to SDAO through rent flowing from V to V . 2 IN OUT 0 resistor R14. Remove R14 if opto-isolated I C func- tionality is desired. V : Supply Output to Load. The LTC2946 measures the OuT current flowing from V to V . 2 IN OUT SDAO: I C Data Output. Connected to SDAI through 0 2 resistor R14. Remove R14 if opto-isolated I C functional- inTV : Internal Low Voltage Supply Input/Output. This CC ity is desired. turret is directly connected to the INTV pin. This turret is CC used to power internal circuitry and can be configured as gpi O1: General Purpose Input/Output 1. Configurable a direct input, as a linear regulator from a higher voltage general purpose output and logic input. Configured by connected to V or as a shunt regulator. In the default DD default as General Purpose Output, pulls low to light D3. configuration with JP1 at V , INTV is internally generated IN CC gpi O2: General Purpose Input/Output 2. Configurable and is 5V. Please see LTC2946 data sheet for more details. general purpose output, logic input, and ACC control input eXTV : External Voltage Supply. This turret can be used DD to gate internal accumulators. By default it is configured as to power the LTC2946 independently of the V power IN ACC input and pulled high so that the energy and charge path. Connect to 4V to 100V external supply if this option accumulation are active. If GPIO2 is configured as an is selected through JP1. output, LED D4 lights up when GPIO2 is asserted low. ADin: Input Measured by the Onboard ADC. Measures gpi O3: General Purpose Input/Output 3. Configurable between 0V to 2.048V. ADIN is loaded with a 140k and general purpose output, logic input, and ALERT output. 3k resistive divider to allow voltage measurements of up By default it is configured as ALERT . As ALERT , it is to 102.4V full scale. pulled to ground when a fault occurs to alert the host controller. LED D5 lights when ALERT is asserted low. dc2156af 2 in