DV2004L1 Fast Charge Development System Control of PNP Power Transistor Features ➤ bq2004 fast-charge control evaluation and development ➤ Charge current sourced from an on-board frequency-modulated linear regulator (up to 3.0A) ➤ Fast charge of 4 to 10 NiCd or NiMH cells and one user-defined selection ➤ Fast-charge termination by delta temperature/delta time (∆T/∆t), negative delta voltage (-∆V) or peak voltage detect, maximum temperature, maximum time, and maximum voltage ➤ -∆V/peak voltage detect, hold-off, top-off, maximum time, and number of cells are jumper-configurable ➤ Programmable charge status display ➤ Discharge-before-charge control with push-button switch or auto discharge-before-charge with jumper ➤ Inhibit fast charge by logic-level input General Description The DV2004L1 Development System provides a development environment for the bq2004 Fast-Charge IC. The DV2004L1 incorporates a bq2004 and a frequencymodulated linear regulator to provide fast charge control for 4 to 10 NiCd or NiMH cells. The fast charge is terminated by any of the following: ∆T/∆t, -∆V or peak voltage detect, maximum temperature, maximum time, maximum voltage, or an inhibit command. Jumper settings select the voltage termination mode, the hold-off, top-off, and maximum time limits, and automatic discharge-before-charge. Connection Descriptions J1 The user provides a power supply and batteries. The user configures the DV2004L1 for the number of cells, voltage, charge termination mode, and maximum charge time (with or without top-off), and commands the discharge-before-charge option with the push-button switch S1. THERM Thermistor connection SNS tor Negative battery terminal and thermisconnection Please review the bq2004 data sheet before using the DV2004L1 board. BAT Positive battery terminal and high side of discharge load LOAD Low side of discharge load GND Ground from charger supply DC JP1 INH 3/98 DC input from charger supply Inhibit input Rev. B Board 1 DV2004L1 JP2 DSEL Display select JP3 VSEL Voltage termination select JP4 TM1 TM1 setting JP5 TM2 TM2 setting JP6 NOC Select number of cells JP7 Auto discharge-before-charge select With the provided NTC thermistor connected between THERM and SNS, values are: LTF = 10°C, HTF = 49°C, and TCO = 50°C. The ∆T/∆t settings at 30°C (T∆T) are: minimum = 0.82°C/minute, typical = 1.10°C/minute. The thermistor is identified by the serial number suffix as follows: Fixed Configuration The DV2004L1 board has the following fixed characteristics : ■ VCC (4.75–5.25V) is regulated on-board from the supply at connector J1 (DC: GND). ■ LEDs indicate charge status. ■ Charge initiates on the later application of the battery or DC, which provides VCC to the bq2004. Thermistor K1 Keystone RL0703-5744-103-S1 (blank) Philips 2322-640-63103 F1 Fenwal Type 16, 197-103LA6-A01 O1 Ozhumi 150-108-00(4) S1 Semetic 103AT-2 Jumper-Selectable Configuration The DV2004L1 must be configured as described below. Pin DCMD may be tied to ground through JP7 for automatic discharge-before-charge. With JP7 open, a toggle of switch S1 momentarily pulls DCMD low and initiates a discharge-before-charge. The bq2004 output activates FET Q1, allowing current to flow through an external current-limiting load between BAT and LOAD on connector J1. INH (JP1): Enables/disables charge inhibit (see bq2004 data sheet). As shipped from Benchmarq, the DV2004L1 frequencymodulated linear regulator is configured to a charging current of 1.13A. This current level is controlled by the value of sense resistor RSNS by the relationship: I CHG = Identifier Jumper Setting Pin State [12]3 Disabled (high) 1[23] Enabled (low) TM1 and TM2 (JP4 and JP5): Select fast charge safety time/hold-off/top-off (see bq2004 data sheet). 0.225V R SNS The value of RSNS at shipment is 0.200Ω. This resistor can be changed depending on the application. The suggested maximum ICHG for the DV2004L1 board is 3A. Q4 must be mounted to an appropriate heat sink. Jumper Setting Pin State [12]3 High 1[23] Low 123 Float Number of Cells (JP6): A resistor-divider network is provided to select 4 to 10 cells (the resulting resistor The maximum cell voltage (MCV) is scaled to 1.8V/cell. Note: Use the bqCharge diskette to calculate the RB1/RB2 resistors to adjust MCV. Rev. B Board 2 Closed Jumper Number of Cells RB25 User-selectable RB24 10 RB23 8 RB22 6 RB21 5 DV2004L1 value equals N 2 – 1 cells). RB1 is a 150KΩ resistor, and RB2 (RB20–RB25) is jumper-selected. Setup Procedure Temperature Disable: Connecting a 10KΩ resistor between THERM and SNS disables temperature control. 1. Configure VSEL, TM1, TM2, DSEL, INH, and number-of-cells (NOC) jumpers. DSEL (JP2): Selects LED1 and LED2 display state (see bq2004 data sheet, Table 2). 2. Connect the provided thermistor or a 10KΩ resistor between THERM and SNS. VSEL (JP3): Selects -∆V or peak-voltage detection, or disables voltage-based termination (see bq2004 data sheet). 3. If using the discharge-before-charge option, connect a current-limiting discharge load between BAT and LOAD. AUTO DIS SELECT (JP7): Jumping JP7 enables automatic discharge-before-charge. 4. Attach the battery pack to BAT and SNS. For temperature control, the thermistor must contact the cells. 5. Attach DC current source to DC (+) and GND (-) connections in J1. (Note: Capacitors C2 and C3 must be changed from those shipped with the board for input voltage in excess of 25V.) Recommended DC Operating Conditions Symbol Description Minimum Typical Maximum Unit IDC Maximum input current - - 3 A VDC Maximum input voltage 2.0 + VBAT or 8.5 - 18 + VBAT or 35 V VBAT BAT input voltage - - 24 V VTHERM THERM input voltage 0 - 5 V IDSCHG Discharge load current - - 2 A Note: Notes Note 1 1. The voltage at R14 is application-specific and limits the dissipation of Q2 to a safe limit during Q4 conduction. See Table 1 for recommended R14 selections per VDC+ and ICHARGE. Rev. B Board 3 DV2004L1 DV2004L1 Board Schematic J1 1 2 3 4 5 6 THERM SNS BAT+ LOAD GND DC D1 R13 +5V 1N5400 C1 1000UF 35V Optional D2 1N4148 U2 78L05ACZ IN C2 1000UF 35V 2K RB1 200K 1% R27 1M Q3 JP6 Number of Cells TIP42 +5V +5V OUT GND C3 100UF 25V 1 JP1 2 3 INH C5 JP7 100UF AUTO_DIS. 6.3V 1 JP2 2 3 DSEL JP3 VSEL +5V JP4 TM1 RT1 4.53K 1% S1 +5V 0.1UF R9 Q1 100K 4 5 6 8 RB20 200K 1% RB21 133K 1% RB22 100K 1% RB23 66.5K 1% 300K R5 27.4K 1% 10 RB24 49.9K 1% RB25 USER_DEF. 1% MTP3055VL 1 2 3 R4 73.2K 1% 1 2 3 4 5 6 7 8 1 2 3 R2 C9 2K DISCHARGE_CMD 1 2 R8 2K 1 2 3 JP5 TM2 RT2 3.57K 1% R12 C7 0.1UF C6 1UF DCMD DSEL VSEL TM1 TM2 TCO TS BAT INH DIS MOD VCC VSS LED2 LED1 SNS R10 16 15 14 13 12 11 10 9 +5V Q2 2N3904 2K R26 100K C4 R11 220 0.1UF U1 BQ2004 C10 0.1UF R1 510K Q4 2N3904 D3 Q5 2N3904 D4 GREEN RSNS 0.2 1% R7 RED R6 120 120 DV2004L1, Rev B, 5-19-97 Rev. 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