C2151PX2 C2152PX2 DS-2742-0905

Primary Sensing SMPS Controller For Offline Applications ADVANTAGES Low cost bipolar primary switch Tight tolerance CV/CC

C2151PX2 C2151PX2 and C2152PX2 C2152PX2 Datasheet Primary Sensing SMPS Controller For Offline Applications ADVANTAGES Low cost bipolar primary switch Tight tolerance CV/CC operation Low component count High efficiency (Energy Star 2.0 compliance with margin) Low no-load power consumption (< 150 mW) Programmable maximum switching frequency Programmable output cable compensation up to 10% C2151PX2 C2151PX2 C2152PX2 C2152PX2 SOT23-6 FEATURES Advanced primary sensing controller achieves true CV/CC output characteristic without opto-coupler Full featured protection for over-temperature, input over-voltage, output short-circuit Advanced PFM/PWM control and quasi-resonant switching for increased efficiency Switching timing jitter spreads RF spectral emissions, eases EMC compliance SOT23-6 package APPLICATIONS Universal input mobile phone chargers. Universal standby and auxiliary power supplies up to 8 W using C2152PX2 C2152PX2 (up to 4 W using C2151PX2 C2151PX2). Figure 1: Typical Application Circuit Using C2151PX2 C2151PX2 Shortform © Cambridge Semiconductor Ltd 2009 Page 1 DS-2742-0905 DS-2742-0905 27-May-2009 C2151PX2 C2151PX2 and C2152PX2 C2152PX2 Datasheet Primary Sensing SMPS Controller For Offline Applications PIN DEFINITIONS SOT23-6 CS 1 6 FB GND 2 5 VDD ED 3 4 RC Figure 2: C2151PX2 C2151PX2 and C2152PX2 C2152PX2 Pin Assignment VDD Pin The VDD pin supplies power to the chip and dictates the operating mode (Run or Sleep). FB Pin The FB pin is used to sense the transformer winding voltage waveform, scaled and AC-coupled by an external RC network (Rfb1, Rfb2 and Cfb in Figure 3). CS Pin The CS pin senses the primary switch current via the current sensing resistor (Rcs in Figure 3). RC Pin The RC timing network connected to the RC pin (shown as Rosc, Cosc in Figure 3) defines both the required maximum switching frequency FMAX and the cable compensation. ED Pin The ED pin is connected to the emitter of the external bipolar junction transistor (Q1 in Figure 3). GND Pin The GND pin provides the ground reference. Shortform © Cambridge Semiconductor Ltd 2009 Page 2 DS-2742-0905 DS-2742-0905 27-May-2009 C2151PX2 C2151PX2 and C2152PX2 C2152PX2 Datasheet Primary Sensing SMPS Controller For Offline Applications TYPICAL APPLICATION The C2151PX2 C2151PX2 and C2152PX2 C2152PX2 controllers are intended primarily for 5 V cellular telephone chargers, but are equally applicable to other off-line applications up to 8 W. A high degree of configurability allows a wide range of applications to be met at minimum cost. A typical application circuit is shown in Figure 3. Figure 3: Universal Input 4 W Charger Typical 4 W Charger Performance Input VIN 85 - 265 V ac Output VOUTNOM 5 V dc (± 5%) IOUTNOM 0.8 A dc (-0/+10%) Cable compensation GCAB 8% Average Efficiency (including cable) KEFF > 66.5% No-load power input PINSTBY < 150 mW Over-temperature protection (OTP) TSH 115 ºC Short-circuit input power PINSC