Lme49600 headphone amplifier evaluation board user's guide national semiconductor application note 1768 kevin hoskins february 29, 2008 quick start guide apply a ±2.5v to ±17v power supply’s voltage to the respec- tive “v + ”, “gnd” and “v - ” pins on ju19 apply a stereo audio signal to the rca jack...
General description the lme49600 is a high performance, low distortion high fi- delity 250ma audio buffer. Whereas there are many uses for the lme49600, this application note describes a headphone amplifier circuit and associated demonstration board. De- signed for use inside an operational amplifie...
Connections connecting to the world is accomplished through a combina- tion of rca jacks, 1/8” stereo headphone jacks and 0.100” headers on the lme49600 demonstration board. The func- tions of the different headers, 1/8” headphone jacks and rca jacks are detailed in table 1. Table 1. Lme49600 demons...
Bill of materials refdes part description value tolerance rating package type manufacturer and part number bat1– bat2 9v battery terminal (male & female) [not installed] keystone 593 (female) & 594 (male) c1 – c8 mulitylayer ceramic capacitor 1.0μf ±20% 25v 805 tdk c2012x5r1e105m c9 c10, c23 – c24 t...
Demonstration board pcb layout figures 3 through 6 show the different layers used to create the lme49600 demonstration board. Figure 3 is the silkscreen that shows parts location. Figure 4 is the top layer. Figure 5 is the bottom layer. Figure 6 is the bottom silkscreen layer. 30047316 figure 3. Top...
30047313 figure 5. Bottom layer 30047314 figure 6. Bottom silk layer www.National.Com 6 an-1768.
Typical performance 30047360 figure 7: thd+n vs output power lme49720/lme49600 headphone amplifier into (from top to bottom at 0.1mw): 16 Ω, 32Ω, 64Ω, 300Ω (v s = ±3v, f = 100hz, 22hz ≤ bw ≤ 22khz) 30047361 figure 8: thd+n vs output power lme49720/lme49600 headphone amplifier into (from top to botto...
30047363 figure 13: thd+n vs output power lme49720/lme49600 headphone amplifier into (from top to bottom at 0.1mw): 16 Ω, 32Ω, 64Ω, 300Ω (v s = ±3v, f = 10khz, 400hz ≤ bw ≤ 80khz) 30047364 14: thd+n vs output power lme49720/lme49600 headphone amplifier into (from top to bottom at 20mw): 16 Ω, 32Ω, 6...
Revision history rev date description 1.0 02/29/08 initial release. 9 www.National.Com an-1768.
Notes an-1768 lme49600 headphone amplifier evaluation board user's guide for more national semiconductor product information and proven design tools, visit the following web sites at: products design support amplifiers www.National.Com/amplifiers webench www.National.Com/webench audio www.National.C...