AIC1781A AIC [Analog Intergrations Corporation], AIC1781A Datasheet
AIC1781A
Related parts for AIC1781A
AIC1781A Summary of contents
Page 1
... Fig. 1 shows an example of charging curve of a battery charged by a fluctuating current from a NiMH battery charger, which uses the AIC1781A controller IC to achieve optimal charging. This technique, in cooperating with the 0 V detection (peak voltage timer), is particularly suitable for NiMH batteries, whose ...
Page 2
... F 4 47nF MPS2222A LED1 VTS 5 GND VCC 6 SEL1 ADJ R14 7 SEL2 SEL3 200K MODE TMR C11 50K 100 AIC1781A R11 100K R13 470K AIC1781A LED3 LED2 R12 GREEN 100K RED 16 R16 R17 15 680 680 ...
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... TOP VIEW 1 PEAK 16 VBT DIS 14 4 VTS 13 5 VCC 12 6 ADJ SEL3 8 9 TMR DSW ORANGE R3 ICON 560 GREEN R4 LED2 560 RED R5 LED1 560 GND SEL1 CC SEL2 V CC MODE V CC AIC1781A DSW ICON LED2 LED1 GND SEL1 SEL2 MODE 3 ...
Page 4
... During Initial Timer After Initial Timer (SEL3>3V) V (SEL3<2V) Battery High (SEL3>3V) (SEL3<2V) Temperature High V Temperature Low Z LED1, LED2, ICON pins ON OFF SEL3 pin I DSW pin I MODE, PEAK, SEL1, SEL2 pins VBT, VTS, ADJ pins R AIC1781A =5V, unless otherwise specified.) CC MIN. TYP. MAX. 4.5 5.0 5.5 CC 1.1 CC 0.11 0.16 0.21 0.63 0.69 0.75 BT 1.1 1.2 1.30 2.6 2 ...
Page 5
... Supply Voltage Temperature ( C) Fig. 6 Safety Timer vs. Temperature 5.0 5.2 5.4 (V) 5.2 5.4 5.6 ( Fig. 7 LED Flashing Frequency vs. (T =25 C, R2=100K , V A 81.5 81.0 80.5 80.0 79.5 79.0 78.5 78.0 4.4 4.6 4.8 5.0 5.2 V (V) CC Fig. 3 Safety Timer vs. Supply Voltage 1.05 1.00 0.95 0.90 0.85 0. Temperature ( C) Fig.5 Supply Current vs. Temperature 5.0 4.8 4.6 4.4 4.2 4.0 3.8 3.6 3.4 - Temperature ( C) AIC1781A =5V, CC 5.4 5 Temperature 5 ...
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... Fig.12 VTS (Low Temp) Limit vs. Temperature 2.28 2.16 2.04 1. Fig Fig.11 Output Impedance vs. Temperature 1.55 1.50 1.45 1.40 1. Fig.13 V AIC1781A (Continued Temperature ( C) VBT (High) Limit vs. Temperature (SEL3<2V Temperature ( C) (LED1, LED2, ICON Pins Temperature ( C) (High Temp) Limit vs. TS Temperature ...
Page 7
... MODE GND VCC Bandgap Reference & MODE Voltage Selection Regulator Charge Control State Machine Battery 13-bit Voltage A/D Protection VBT AIC1781A Temperature ( C) VBT (Low) Limit vs. Temperature (SEL3<2V, After Initial Timer) TMR LED2 Oscillator LED1 Display Control Unit ICON Charge Control Unit ...
Page 8
... DIS is active AIC1781A mode. PIN 4: VTS- The battery cell temperature is represented as a voltage input to the AIC1781A at this pin. The acceptable voltage range of VTS pin is 0.29V 0.72V . CC temperature is regarded as too high if the voltage of VTS pin is lower than 0.29V ...
Page 9
... After the battery passes fault checks and required discharging of the battery is completed, fast charging begins while initial timer and safety timer of the AIC1781A start counting. Functions detection, peak voltage timer, and maximum battery voltage are, however, disabled temporarily until the initial timer period in the initial stage of a charge cycle elapses ...
Page 10
... DSW pin should be around 32.8 KHz. After the safety timer period is finished, the fast charge action is terminated. Maximum Voltage and Temperature Cutoff The AIC1781A guards against the maximum limits for battery voltage and temperature during fast charging. If either of these limits is exceeded, fast charge action is terminated. ...
Page 11
... Battery Temperature Measurement The AIC1781A employs a negative temperature coefficient (NTC) thermistor to measure the battery’ s temperature. The thermistor is inherently 120 nonlinear with respect to temperature. To reduce 91 the effect of nonlinearity, a resistor-divider network 62 in parallel with the thermistor is recommended typical application circuit is shown in Fig ...
Page 12
... Disabled If Peak Timer Period has Finished No If 0.25% Decline of VBT is Detected has Reached Safety Timer Period has Finished Fig. 16 Function Flow Chart of AIC1781A LED's Display Abnormal, No ICON ON, Safety Timer Reset Yes If SEL3>VCC-0. VCC/2-0.4V>SEL3 >1.4V If SEL3>VCC-0.3V No Yes or VCC/2-0.4V> ...
Page 13
... TABLE 5 Values of Rx and - 551.1 300.7 204.8 153.9 122.8 101.8 Setting the ADJ Pin Voltage 86.5 The slope detection is determined by ADJ pin voltage of the AIC1781A. 75.0 66.0 The calculation of ADJ pin voltage is shown in the 58.7 following procedure followed by an example. 52.8 47.8 43.6 39.9 36.8 AIC1781A 65 5 ...
Page 14
... We have VBT Range and Temperature Protection The acceptable voltage range of VBT pin and mode of temperature protection function is determined by the voltage of SEL3 pin, shown as the following: is BASE (a) SEL3 > V AIC1781A 0.75 1.0 ( C/min.) ( C/min.) 0.45 0.60 0.90 1.20 1.35 1.80 1.80 2 ...
Page 15
... When the MODE pin is biased to GND, the function detection is disabled. When the MODE pin is biased to VCC, the AIC1781A enters the test mode. The test mode can be used to significantly reduce production test time. For relevant informations please contact AIC directly ...
Page 16
... Test Mode Fig. 20 shows the timing diagram for externally open-drained controlled PEAK, ADJ, VBT, VTS, SEL1 and SEL2 pin voltages of a recommended AIC1781A test scheme, utilizing TEST mode function. Output waveforms of LED1, LED2 and ICON of a properly functioning AIC1781A are also shown in the figure ...
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... Fig INITIAL TIMER 0V 1.12V 1.9V 1.993V (-0.35 OFF ON 3.2KHz ON OFF Floating Floating Floating GND 0.32 0.12 0.32 0 1.18 1.5 1.62 1.94 Timing Diagram of AIC1781A in Test Mode SAFETY TIMER TEST T/ t TEST 2V 2mV Step/100mS 4V 2V 1.97V 1.85V 2mV (-2.15%) Step/100mS (-2.5%) OFF ON ON OFF ON GND GND Floating GND 0.5 0.24 0 2.64 3.14 3.38 3.78 AIC1781A < ...
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... AIC1781A SYMBOL MIN MAX A 2.35 A1 0.10 B 0.33 C 0.23 D 10.10 10. ...