adp3811 Analog Devices, Inc., adp3811 Datasheet
adp3811
Available stocks
Related parts for adp3811
adp3811 Summary of contents
Page 1
... The ADP3810 has internal thin-film resistors that are trimmed to provide a precise final voltage for LiIon batteries. Four volt- age options are available, corresponding to 1-4 LiIon cells as follows: 4.2 V, 8.4 V, 12.6 V and 16.8 V. The ADP3811 omits these resistors allowing any battery volt- age to be programmed with external resistors. FUNCTIONAL BLOCK DIAGRAM V ...
Page 2
... Units –315 –300 –285 mV –32 –25 –18 mV 0.0 1 –1.0 +1.0 % 210k 420k 630k 840k –2.5 +2 2.000 V –1.0 +1.0 % –1.8 +1.8 % –0.25 +0.25 % 0.004 0. 0.1 0 V/V 2.65 2.7 V 2.5 2 for the ADP3811. SENSE REV. 0 ...
Page 3
... Input Range . . . . . . . . . . . . . . . . . . –0 CTRL CS V Input Range (ADP3811 –0 SENSE V Input Range (ADP3810 –0 SENSE Maximum Power Dissipation . . . . . . . . . . . . . . . . . . 500 mW Operating Temperature Range . . . . . . . . . . . – +85 C Storage Temperature Range . . . . . . . . . . . . . – 150 C Lead Temperature (Soldering, 10 sec) ...
Page 4
... ADP3810/ADP3811 –Typical Performance Characteristics 2.004 V = +10V CC 2 TYPICAL PARTS I = 100µA L 2.002 C = 0.1µF L 2.000 1.998 1.996 1.994 –50 – 100 TEMPERATURE – C Figure 2. Reference Output Voltage vs. Temperature for Two Typical Parts – +10V 100µA – 0.1µF L – ...
Page 5
... FREQUENCY – Hz Figure 11. GM2 Open-Loop Gain and Phase vs. Frequency 1 +10V CC 0.5 0 –0.5 –1.0 –1.5 –50 – 100 TEMPERATURE – C Figure 14. ADP3811 GM2 Offset vs. Temperature 2 + 2.0 1.5 1.0 0 SUPPLY VOLTAGE, V – Volts CC Figure 17. ADP3811 V Bias SENSE Current vs ...
Page 6
... COMP Distribution APPLICATIONS SECTION Functional Description The ADP3810 and ADP3811 are designed for charging NiCad, NiMH and LiIon batteries. Both parts provide accurate voltage sense and current sense circuitry to control the charge current and final battery voltage. Figure 1 shows a simplified battery charging circuit with the ADP3810/ADP3811 controlling an external dc-dc converter ...
Page 7
... The main difference between the ADP3810 and the ADP3811 is illustrated in Figure 1. The resistors R1 and R2 are external for the ADP3811 and internal for the ADP3810. The ADP3810 is specifically designed for LiIon battery charging, and thus, the internal resistors are precision thin-film resistors laser trimmed for LiIon cell voltages ...
Page 8
... This is tested in a full feedback loop so that the single ac- curacy specification given in the specification table accounts for is lower accuracy all of the errors mentioned above. For the ADP3811, the resis- CS tors are external, so the final voltage accuracy needs to be deter- mined by the designer. Certainly, the tolerance of the resistors has a large impact on the final voltage accuracy, and 1% or bet- ter is recommended ...
Page 9
... V (e.g., with a shorted battery bat- tery discharged below it’s minimum voltage), the ADP3810/ ADP3811 will be in Undervoltage Lock Out (UVLO) and will not drive the optocoupler. In this condition, the primary PWM circuit will run at its designed current limit. The V ADP3810/ADP3811 can be boosted using the circuit shown in Figure 23 ...
Page 10
... ADP3810/ADP3811 battery voltage is at least 1.5 V with a programmed charge cur- rent of 0.1 A. For a higher programmed charge current, the battery voltage can drop below 1.5 V, and V above 2.7 V. This is because of the additional energy in the flyback transformer, which transfers more energy through the 10 nF capacitor The 22 F bypass capacitor stores the energy transferred through the 10 nF capacitor ...
Page 11
... The voltage loop directly senses the battery voltage. Since the ADP3810 is used in this circuit instead of the ADP3811 connected directly to the battery. The internal resistors set the battery voltage to 8 this case. Of course, other voltage ...
Page 12
... Buck Converter (Figure 28 Linear Regulator (Figure 29). GM1 and GM2 b. NPN Darlington are the internal GM amplifiers of the ADP3810/ADP3811, and GM3 is the buffered output stage that drives the optocoupler. The primary side in Figure 23 is represented here by the “Power Stage,” ...
Page 13
... Power Stage (General): GM4 = Power Stage (Voltage Loop): GM4 = 0.091 A/V Power Stage (Current Loop): GM4 = 1.0 A/V The gains for the ADP3810/ADP3811 GM amplifiers are based on typical measurements of the IC’s open-loop gain, and they are expressed in units of milliamps per volt. The dc voltage gain REV. 0 GM4 1nF 1 ...
Page 14
... To simplify the analysis further, the loop gain is split into two components: the gain from the battery to the ADP3810/ ADP3811’s COMP pin and the gain from the COMP pin back to the battery. Because the compensation of each loop depends upon the RC network on the COMP pin convenient choice for dividing the loop calculations ...
Page 15
... C the effective gain calculated at 1.9 kHz, the impedance of C the gain becomes 1.9 kHz EA G LOSS = 38.9 dB – 13 25.5 dB –15– ADP3810/ADP3811 ), f , and f LOOP PM 20 log GM 3 ITX 0.36 3 log ...
Page 16
... ADP3810/ADP3811 Step 14. Calculate value realize G C2 Assuming that short, R forms a resistor divider with C2 C2 R3, reducing the loop gain. To calculate R tor ratio to give an attenuation of 25.5 dB, which is a loss of 1/20 provide some margin in the circuit for gain fluctuations in ...