SLOA044A March   2000  – June 2021 TL2842 , TL2842B , TL2843 , TL2844 , TL2845 , TL3842 , TL3842B , TL3843 , TL3844 , TL3845 , TLC081 , TLC2201 , TLV2231 , TLV2361 , TLV2362 , TLV2470 , TLV2471 , TLV2770 , TLV2771 , TLV341 , TLV342 , UC1842 , UC1843 , UC1844 , UC1845 , UC2842 , UC2842A , UC2843 , UC2843A , UC2844 , UC2844A , UC2845 , UC2845A , UC3841 , UC3842 , UC3842A , UC3842M , UC3843 , UC3843A , UC3844 , UC3844A , UC3845 , UC3845A , UC3845AM , UCC1800 , UCC1801 , UCC1802 , UCC1803 , UCC1804 , UCC1805 , UCC2800 , UCC2801 , UCC2802 , UCC2802M , UCC2803 , UCC2804 , UCC2805 , UCC2813-0 , UCC2813-1 , UCC2813-2 , UCC2813-3 , UCC2813-4 , UCC2813-5 , UCC28C40 , UCC28C41 , UCC28C42 , UCC28C43 , UCC28C44 , UCC28C45 , UCC3801 , UCC3802 , UCC3803 , UCC3804 , UCC3805 , UCC3813-0 , UCC3813-1 , UCC3813-2 , UCC3813-3 , UCC3813-4 , UCC3813-5 , UCC38C40 , UCC38C41 , UCC38C42 , UCC38C43 , UCC38C44 , UCC38C45

 

  1. 1Introduction
  2. 2Circuit Design
  3. 3Advantages
  4. 4Choosing the Op Amp
  5. 5Conclusion
  6. 6Revision History

5 Conclusion

The use of an op amp to differentially-amplify a current-sense signal in switch-mode power supplies offers cost, programmability, performance and power advantages. This paper discusses how to choose the proper op amp for this particular application. Several single-supply op amps suggested for this application are detailed in Table 5-1, with significant parameters listed. The TLV2771 and TLC081 are well suited for this application in 3.3-V and 5-V systems, respectively.

Table 5-1 Suggested Texas Instruments Op Amps for Current Sensing

OP AMP

P/N

SUPPLY VOLTAGE

[V]

SUPPLY CURRENT

[mA] (MAX)

SLEW RATE

[V/us] (TYP)

GBW

[MHz] (TYP)

 SMD PACKAGES

TLV2770

TLV2771

 2.5–5.5 2.0 9.0 4.8 SOT–23, SOIC–8, MSOP–8
TLV2361 2.0–5.0 2.5 3.0 7.0 SOT–23

TLV2470

TLV2471

 2.7–6.0 0.75 1.4 2.8 SOT–23, SOIC–8
TLV2231 2.7–10.0 1.2 1.6 2.0
TLC081 4.5–16.0 2.5 16.0 10.0 MSOP–8, SOIC–8
TLC2201 4.6–16.0 1.5 2.5 1.6 SOIC–8